A 15-year-old girl has been charged with first-degree murder after she allegedly stabbed a 15-year-old boy aboard a Washington, DC, Metro train.

Police say Jaquar McNair, 15, was fatally stabbed inside an Orange Line Train by the U.S. Capitol building around midday on Friday. The boy died from his injuries on Saturday morning, the Associated Press reported.

The stabbing occurred at D.C. Metro’s Capitol South metro station, which is a block away from the Cannon House Office building where some members of Congress have their offices.

Police say the initial attack came from a dispute among a group of teens. McNair, who was injured at the time, walked up to the Metro station’s kiosk around 12:30 p.m. before he collapsed, CBS News reported.

He was taken to a local hospital to undergo surgery before he died from his wounds.

The U.S. Capitol Police found the 15-year-old suspect, whose name has not yet been released, several blocks from the Metro, WUSA reported.

The suspect was initially arrested on a charge of assault with intent to kill but prosecutors upgraded the charge to first-degree murder following McNair’s death.