Multiple angles of surveillance footage from Tuesday's shooting have been released by merchants at the Tanforan mall in San Bruno, and it depicts the chaos of fleeing teenagers on the mall's second floor. And it's all teenagers being stupid..

In what San Bruno police Chief Ed Barberini is calling "a silly, stupid, tragic event," two possibly teenage shooters shot "at each other, or someone else" in the middle of a busy shopping mall Tuesday afternoon, leaving two teenagers with grave injuries.

An active shooter situation Tuesday afternoon at San Bruno's Tanforan mall shut down the San Bruno BART station and prompted a large police response. The shooting suspect or suspects remain at large, and two teenagers were shot.