Russia explosion

Russian President Vladimir Putin lays flowers at a place near the Tekhnologichesky Institut subway station in St.Petersburg, Russia, Monday, April 3, 2017.

A bomb blast tore through a subway train deep under Russia’s second-largest city Monday, killing several people and wounding many more in a chaotic scene that left victims sprawled on a smoky platform.

(Mikhail Klimentyev/Pool Photo via AP)