Two explosions occurred near the finish line at the Boston Marathon on Monday about four hours after the start of the race.
At least three people were killed, and more than 170 were wounded.

BOSTON — The explosives that killed three people and injured more than 170 during the Boston Marathon on Monday were most likely rudimentary devices made from ordinary kitchen pressure cookers, except they were rigged to shoot sharp bits of shrapnel into anyone within reach of their blast and maim them severely, law enforcement officials said Tuesday.

People signing a banner out out for victims to show support