Investigators are trying to determine how an inmate from a Washington, D.C. jail managed to escape from custody and crawl under a bus used to transport prisoners to court.

27-year-old Simmie Bellamy of Southwest Washington was killed yesterday after falling from the undercarriage of the bus at the entrance to the Third Street Tunnel. Authorities say he was hit by cars at the intersection of 3rd and D streets in Northwest.

Bellamy was initially being taken by the U.S. Marshals Service to a hearing in DC Superior Court. He still had handcuffs on when his was hit.