The 15-year-old girl thought the three security guards in the Seattle bus tunnel would protect her from attack.

She was wrong.

As the footage below shows, the guards watched and did nothing as the girl was punched, thrown to the ground, kicked repeatedly in the face and then robbed.

The girl told a detective that the group followed her from a nearby department store into the bus tunnel.

The guards didn't intervene because they have standing orders to "observe and report," but not to try to stop fights or criminal activity. That protocol is now under review.

The statements were revealed in court papers filed Wednesday against the teenage girl who attacked the victim and the three young men accused of stealing her purse, phone and iPod. All four were charged with robbery.

Although she was not hospitalized, the victim said she lost consciousness during the attack and had to see a doctor.

The incident, which occurred on January 28, is being investigated by the King County Sheriff's Office and the Metro Transit Police, said sheriff's office spokesman Sgt. John Urquhart.

"Transit tunnel security officers were on the platform and witnessed the assault," said Urquhart in a statement. "However they did not intercede as they are unarmed, civilian employees."

Metro Transit General Manager Kevin Desmond did not agree.

"We are very disappointed in what people see in that video," Desmond said. "It was absolutely unacceptable. I know the Olympic Security folks were also disappointed in the response, but again, the employees were following the letter of the agreement."

The Seattle Times published an editorial shortly after the video was released Wednesday condemning the inaction of the guards and questioning the multibillion-dollar contract the transit authority has with private security firms.

What indeed are taxpayers and transit riders paying for? Three security guards doing nothing. One would be plenty, given the job description and expectations. So the message for the traveling public is simple: There is no security in the bus tunnel. If a rider needs directions or perhaps has some self-esteem issues to discuss, maybe — maybe — the folks in the reflective vests can help.

Otherwise, tough luck. You are on your own.

The Associated Press contributed to this report.