Immigrant children are led by staff in a single file between tents at a detention facility next to the Mexican border in Tornillo, Texas, U.S., June 18, 2018. Picture taken June 18, 2018. REUTERS/Mike Blake/File Photo SEARCH "POY DECADE" FOR THIS STORY. SEARCH "REUTERS POY" FOR ALL BEST OF 2019 PACKAGES. TPX IMAGES OF THE DAY. 

Migrant children are led by staff in single file between tents at a detention facility next to the Mexican border in Tornillo, Texas June 18, 2018. REUTERS/Mike Blake SEARCH "PULITZER REUTERS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY 

Migrant children are led by staff in single file between tents at a detention facility next to the Mexican border in Tornillo, Texas June 18, 2018. REUTERS/Mike Blake 

Immigrant children are led by staff in single file between tents at a detention facility next to the Mexican border in Tornillo, Texas, U.S., June 18, 2018. Reuters photographer Mike Blake: "It was a lot of teamwork that made this picture happen, from finding the location to hunting down an aircraft for aerials while I flew into Texas on a commercial flight. The Trump administration's new policy of separating migrant children from their parents at the border had begun, but no one really understood until these images were transmitted out to the world the scale and reality of what was going on. After factoring in flight time to the camp, I asked the pilot to wait on the ground for an hour, thinking there was more likely to be movement around dinner time, the light being better then as well. This image was shot with a 600mm lens from 1,000 feet out the window of a small plane as we circled near the little town of Tornillo, Texas on the U.S.-Mexican border. The flight was hot and bumpy and the turbulence made it extremely difficult to even frame the image in the viewfinder. Reuters was the first to show such aerial images of the camp and, in the next morning when both the New York Times and Washington Post fronted their print editions with what I had photographed, President Trump signed an order ending the separation policy." REUTERS/Mike Blake SEARCH "IMMIGRATION POY" FOR THIS STORY. SEARCH "REUTERS POY" FOR ALL BEST OF 2018 PACKAGES. TPX IMAGES OF THE DAY. 

Immigrant children are led by staff in single file between tents at a detention facility next to the Mexican border in Tornillo, Texas, U.S., June 18, 2018. Picture taken June 18, 2018 REUTERS/Mike Blake SEARCH "POY GLOBAL" FOR FOR THIS STORY. SEARCH "REUTERS POY" FOR ALL BEST OF 2018 PACKAGES. TPX IMAGES OF THE DAY. 

Immigrant children are led by staff in single file between tents at a detention facility next to the Mexican border in Tornillo, Texas, U.S., June 18, 2018. Reuters photographer Mike Blake: "It was a lot of teamwork that made this picture happen, from finding the location to hunting down an aircraft for aerials while I flew into Texas on a commercial flight. The Trump administrationÕs new policy of separating migrant children from their parents at the border had begun, but no one really understood until these images were transmitted out to the world the scale and reality of what was going on. After factoring in flight time to the camp, I asked the pilot to wait on the ground for an hour, thinking there was more likely to be movement around dinner time, the light being better then as well. This image was shot with a 600mm lens from 1,000 feet out the window of a small plane as we circled near the little town of Tornillo, Texas on the U.S.-Mexican border. The flight was hot and bumpy and the turbulence made it extremely difficult to even frame the image in the viewfinder. Reuters was the first to show such aerial images of the camp and, in the next morning when both the New York Times and Washington Post fronted their print editions with what I had photographed, President Trump signed an order ending the separation policy." REUTERS/Mike Blake SEARCH "POY STORY" FOR THIS STORY. SEARCH "REUTERS POY" FOR ALL BEST OF 2018 PACKAGES. TPX IMAGES OF THE DAY. 

Immigrant children are led by staff in single file between tents at a detention facility next to the Mexican border in Tornillo, Texas, U.S., June 18, 2018. Picture taken June 18, 2018 REUTERS/Mike Blake SEARCH "POY GLOBAL" FOR FOR THIS STORY. SEARCH "REUTERS POY" FOR ALL BEST OF 2018 PACKAGES. TPX IMAGES OF THE DAY. 

Immigrant children, many of whom have been separated from their parents under a new "zero tolerance" policy by the Trump administration, are being housed in tents next to the Mexican border in Tornillo, Texas, U.S. June 18, 2018. REUTERS/Mike Blake -RC188AFA93B0 

Immigrant children, many of whom have been separated from their parents under a new "zero tolerance" policy by the Trump administration, are being housed in tents next to the Mexican border in Tornillo, Texas, U.S. June 18, 2018. REUTERS/Mike Blake -RC188AFA93B0 

New York Mayor Bill De Blasio walks to the entrance to try and gain access to the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

New York Mayor Bill De Blasio greets a demonstrator outside a children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

A federal officer closes a gate, as New York Mayor Bill De Blasio approaches to ask for access to the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

New York Mayor Bill De Blasio speaks to a federal officer through a chain linked fence asking for access to the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Federal officers open and close a gate to let out vehicles as mayors from across the U.S. are surrounded by media at the front entrance of the children's tent encampment in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Los Angeles Mayor Eric Garcetti records with his phone outside of the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Federal officers stand guard at the front entrance outside of the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

New York Mayor Bill De Blasio listens as a group of mayors from across the U.S. gather outside of the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

New York mayor Bill De Blasio speaks to a DHS officer through a chain linked fence outside of the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Stephen Benjamin, mayor of Columbia, South Carolina, and a bipartisan delegation of mayors from across the country speak to media near a detention facility where children of migrants are being held, at the port of entry in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake TPX IMAGES OF THE DAY 

A pile of kids shoes left by mayors from U.S. cities lay at the front gate outside of the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake TPX IMAGES OF THE DAY 

A small group of demonstrators protests outside of the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Stephen Benjamin, mayor of Columbia, South Carolina speaks as mayors from across the U.S. gather outside of the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Los Angeles Mayor Eric Garcetti speaks with a group of mayors from across the U.S. outside of the childrens tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Mayors from all across the U.S. gather for a press conference outside the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

A protester holds up a sign as mayors from U.S. cities are stopped from entering the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Los Angeles mayor Eric Garcetti hugs Elizabeth J. Kistin Keller the wife of Albuquerque mayor Tim Keller outside the children's tent encampment following a group of U.S. mayors press conference Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Albuquerque mayor Tim Keller leaves a stuff animal outside of the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Seattle mayor Jenny Durkan delivers a pair of shoes to the front gated chain link fence outside the children's tent encampment in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

New York mayor Bill De Blasio speaks to a DHS officer through a chain linked fence outside of the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

A protester holds up a sign as mayors from U.S. cities are stopped from entering the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

A pile of kids shoes left by mayors from U.S. cities lay at the front gate outside of the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

New York mayor Bill De Blasio speaks to a DHS officer through a chain linked fence outside of the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Seattle mayor Jenny Durkan asks for access but is denied, as she speaks to a DHS officer through a chain linked fence outside the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

After being denied access New York mayor Bill De Blasio looks through a chain linked fence outside of the children's tent encampment built to deal with the Trump administrations "zero tolerance" policy in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Shoes and toys are left at the gate in protest by a bipartisan delegation of mayors from across the country at a detention facility where children of migrants are being held, at the port of entry in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Columbia, South Carolina mayor Stephen Benjamin shakes hands with Los Angeles mayor Eric Garcetti (R) after being informed that the White House will stop prosecuting migrant parents who cross the border illegally with children outside a detention facility where children of migrants are being held, at the port of entry in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

New York mayor Bill de Blasio speaks to media after being denied access to a detention facility where children of migrants are being held, at the port of entry in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

New York mayor Bill de Blasio (L) is denied access to a detention facility where children of migrants are being held, at the port of entry in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

A woman holds up a sign as mayors from a bipartisan delegation of mayors from across the country speak to media near a detention facility where children of migrants are being held, at the port of entry in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Jenny Durkan, mayor of Seattle, Washington, and a bipartisan delegation of mayors from across the country speak to media near a detention facility where children of migrants are being held, at the port of entry in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Mayors from a bipartisan delegation of mayors from across the country speak to media near a detention facility where children of migrants are being held, at the port of entry in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Los Angeles mayor Eric Garcetti and a bipartisan delegation of mayors from across the country speak to media near a detention facility where children of migrants are being held, at the port of entry in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Stephen Benjamin, mayor of Columbia, South Carolina, and a bipartisan delegation of mayors from across the country speak to media near a detention facility where children of migrants are being held, at the port of entry in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Los Angeles mayor Eric Garcetti arrives to join a bipartisan delegation of mayors from across the country near a detention facility where children of migrants are being held, at the port of entry in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

New York City Mayor Bill de Blasio arrives to join a bipartisan delegation of mayors from across the country near a detention facility where children of migrants are being held, at the port of entry in Tornillo, Texas, U.S. June 21, 2018. REUTERS/Mike Blake 

Security officers keep watch over a tent encampment housing immigrant children just north of the Mexican border in Tornillo, Texas, U.S. June 20, 2018. REUTERS/Mike Blake TPX IMAGES OF THE DAY 

Retired army veteran Paul Garcia parks his car and takes a prayer outside a tent encampment housing immigrant children in Tornillo, Texas, U.S. June 20, 2018. REUTERS/Mike Blake 

A security officer keeps watch over a tent encampment housing immigrant children just north of the Mexican border in Tornillo, Texas, U.S. June 20, 2018. REUTERS/Mike Blake 

A department of Homeland Security helicopter hovers near a tent encampment housing immigrant children just north of the Mexican border in Tornillo, Texas, U.S. June 20, 2018. REUTERS/Mike Blake 

Security officers keep watch over a tent encampment housing immigrant children just north of the Mexican border in Tornillo, Texas, U.S. June 20, 2018. REUTERS/Mike Blake 

Security officers keep watch over a tent encampment housing immigrant children just north of the Mexican border in Tornillo, Texas, U.S. June 20, 2018. REUTERS/Mike Blake 

Security officers keep watch over a tent encampment housing immigrant children just north of the Mexican border in Tornillo, Texas, U.S. June 20, 2018. REUTERS/Mike Blake 

Security officers keep watch over a tent encampment housing immigrant children just north of the Mexican border in Tornillo, Texas, U.S. June 20, 2018. REUTERS/Mike Blake 

Local school district leaders call for an end to the separation policy of immigrant children as they stand near a tent encampment housing children under the new "zero tolerance" policy by the Trump administration in Tornillo, Texas, U.S. June 20, 2018. REUTERS/Mike Blake 

Immigrant children now housed in a tent encampment under the new "zero tolerance" policy by the Trump administration are shown walking in single file at the facility near the Mexican border in Tornillo, Texas, U.S. June 19, 2018. REUTERS/Mike Blake 

Immigrant children now housed in a tent encampment under the new "zero tolerance" policy by the Trump administration are shown walking in single file at the facility near the Mexican border in Tornillo, Texas, U.S. June 19, 2018. REUTERS/Mike Blake 

Immigrant children now housed in a tent encampment under the new "zero tolerance" policy by the Trump administration are shown walking in single file at the facility near the Mexican border in Tornillo, Texas, U.S. June 19, 2018. REUTERS/Mike Blake TPX IMAGES OF THE DAY 

The high school football field is shown in the town of Tornillo, Texas, U.S. June 19, 2018. REUTERS/Mike Blake 

Immigrant children now housed in a tent encampment under the new "zero tolerance" policy by the Trump administration are shown walking in single file at the facility near the Mexican border in Tornillo, Texas, U.S. June 19, 2018. REUTERS/Mike Blake 

Workers construct tents and a playing field for immigrant children housed at an encampment under the new "zero tolerance" policy by the Trump administration near the Mexican border in Tornillo, Texas, U.S. June 19, 2018. REUTERS/Mike Blake