Security Guards Watch as Girl, 15, Beaten in Seattle Metro Bus Tunnel

Three security guards watched a group of teens punch, kick and rob a 15-year-old girl in the downtown Seattle Metro bus tunnel without intervening.

Security video shows the guards call for help on their radios, but they don't go to the aid of the girl even as she is being kicked in the head.

A dispute involving a group of 10 teens apparently started inside a department store the evening of Jan. 28 and moved to the bus tunnel at Westlake Station, where the girl was attacked.

The King County sheriff's office tells KING-TV four suspects, ages 15 to 20, have been arrested in the investigation.

Metro Transit General Manager says it's revising its policy that guards only "observe and report" problems.