A special South Korean rescue team boat is seen in silhouette near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

A special South Korean rescue team boat is seen near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

A special South Korean rescue team boat passes by a military boat anchored by Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

A woman leaves flowers near Margaret Bridge to pay respects to the victims of a ship accident, which killed several people on the Danube river, in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

People look at the site of a ship accident, which killed several people on the Danube river, in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

People pay respects to the victims of a ship accident, which killed several people on the Danube river, near Margaret Bridge in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

A rescue team is seen on a boat at the site of a ship accident, which killed several people on the Danube river, in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

A woman prays near Margaret Bridge to mourn the victims of a ship accident, which killed several people on the Danube river, in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

A woman lays down a red rose to mourn the victims of a ship accident, which killed several people on the Danube river, in Budapest, Hungary, May 31, 2019. REUTERS/Bernadett Szabo 

Flowers and a note with Korean and Hungarian flags is seen on Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

Women pray to mourn the victims of a ship accident, which killed several people on the Danube river, in Budapest, Hungary, May 31, 2019. REUTERS/Bernadett Szabo TPX IMAGES OF THE DAY 

A diver of a special South Korean rescue team enters the water at the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic TPX IMAGES OF THE DAY 

Women pray to mourn the victims of a ship accident, which killed several people on the Danube river, in Budapest, Hungary, May 31, 2019. REUTERS/Bernadett Szabo 

A woman lays down a white rose to mourn the victims of a ship accident, which killed several people on the Danube river, in Budapest, Hungary, May 31, 2019. REUTERS/Bernadett Szabo 

A woman lays down a white rose to mourn the victims of a ship accident, which killed several people on the Danube river, in Budapest, Hungary, May 31, 2019. REUTERS/Bernadett Szabo 

People pay tribute to the victims of a ship accident, which killed several people on the Danube river, in Budapest, Hungary, May 31, 2019. REUTERS/Bernadett Szabo 

A woman pays tribute to the victims of a ship accident, which killed several people on the Danube river, in Budapest, Hungary, May 31, 2019. REUTERS/Bernadett Szabo 

A fire brigade rescue ship and a police boat are seen at the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Bernadett Szabo 

A rescue team helps a diver out of the water at the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

Family members of victims of a ship accident on the Danube river arrive at Ferenc Liszt International Airport in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

A family member of victims of a ship accident on the Danube river sits on a car as he arrives at Ferenc Liszt International Airport in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

A rescue team assists a diver at the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

Family members of victims of a ship accident on the Danube river arrive at Ferenc Liszt International Airport in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

Family members of victims of a ship accident on the Danube river arrive at Ferenc Liszt International Airport in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

Family members of victims of a ship accident on the Danube river arrive at Ferenc Liszt International Airport in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

A rescue team is seen at the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Bernadett Szabo 

A rescue team helps a diver out of the water at the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

A rescue boat is seen at the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Bernadett Szabo 

A diver of a special South Korean rescue team enters the water at the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

A diver of a special South Korean rescue team enters the water at the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

A diver of a special South Korean rescue team enters the water at the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

People look at a special South Korean rescue team at the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

A special South Korean rescue team is seen on a boat at the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

Special South Korean rescue team is seen at the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

Special South Korean rescue team arrive at Ferenc Liszt International Airport in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

Special South Korean rescue team arrive at Ferenc Liszt International Airport in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

Special South Korean rescue team sit on a bus as they arrive at Ferenc Liszt International Airport in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

Special South Korean rescue team sit on a bus as they arrive at Ferenc Liszt International Airport in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

Special South Korean rescue team arrive at Ferenc Liszt International Airport in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

Special South Korean rescue team arrive at Ferenc Liszt International Airport in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

Special South Korean rescue team arrive at Ferenc Liszt International Airport in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

Special South Korean rescue team arrive at Ferenc Liszt International Airport in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

Special South Korean rescue team arrive at Ferenc Liszt International Airport in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

Special South Korean rescue team arrive at Ferenc Liszt International Airport in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

Special South Korean rescue team arrive at Ferenc Liszt International Airport in Budapest, Hungary, May 31, 2019. REUTERS/Marko Djurica 

Hungarian Foreign Minister Peter Szijjarto and South Korean Foreign Minister Kang Kyung-wha leave after visiting the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

Hungarian Foreign Minister Peter Szijjarto and South Korean Foreign Minister Kang Kyung-wha leave after visiting the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

Hungarian Foreign Minister Peter Szijjarto and South Korean Foreign Minister Kang Kyung-wha leave after visiting the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

Hungarian Foreign Minister Peter Szijjarto and South Korean Foreign Minister Kang Kyung-wha visit the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

South Korean Foreign Minister Kang Kyung-wha arrives at the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

Hungarian Foreign Minister Peter Szijjarto and South Korean Foreign Minister Kang Kyung-wha arrive at the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

Hungarian Foreign Minister Peter Szijjarto and South Korean Foreign Minister Kang Kyung-wha arrive at the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

A military ship is seen near the site of a ship accident, which killed several people, on the Danube river in Budapest, Hungary, May 31, 2019. REUTERS/Antonio Bronic 

People sit under the Margaret Bridge near the site of a ship accident, which killed several people, on the Danube river in Budapest, Hungary, May 30, 2019. REUTERS/Marko Djurica 

A man lights candles next to the Margaret Bridge near the site of a ship accident, which killed several people, on the Danube river in Budapest, Hungary, May 30, 2019. REUTERS/Marko Djurica 

A member of a rescue team is seen in a boat as candles burn on the Margaret Bridge near the site of a ship accident, which killed several people, on the Danube river in Budapest, Hungary, May 30, 2019. REUTERS/Marko Djurica 

Flowers are attached to the railing of the Margaret Bridge near the site of a ship accident, which killed several people, on the Danube river in Budapest, Hungary, May 30, 2019. REUTERS/Marko Djurica 

A floating crane is seen at the site of a ship accident, which killed several people, near Margaret Bridge on the Danube river in Budapest, Hungary, May 30, 2019. REUTERS/Marko Djurica TPX IMAGES OF THE DAY 

Flowers are placed near the site of a ship accident, which killed several people, on the Danube river in Budapest, Hungary, May 30, 2019. REUTERS/Marko Djurica 

A rescue vessel is seen under the Margaret Bridge near the site of a ship accident, which killed several people, on the Danube river in Budapest, Hungary, May 30, 2019. REUTERS/Marko Djurica