People walk past flowers left on a floor in memory of those killed in Monday's blast at Moscow's Domodedovo airport January 25, 2011. Russia's President Dmitry Medvedev ordered investigators on Tuesday to root out the culprits behind a deadly bombing at Russia's busiest airport and threatened sackings over security lapses he said had aided the attack. REUTERS/Denis Sinyakov (RUSSIA - Tags: CRIME LAW TRANSPORT IMAGES OF THE DAY)