Philadelphia police were investigating the beatdown of two Benjamin Franklin High School students on a subway platform that was caught on camera and went viral on YouTube — but nobody called 911 about.

About a dozen students appear to take part in the attack at the Spring Garden station in the video, which is timestamped as starting at 3:15 p.m.

In the attack, which appeared to last for 1 minute and 5 seconds, the mob stomps on the head of one of the victims. One of the assailants is even seen falling onto the subway tracks before jumping back up and into the mob again.

SEPTA Police Chief Thomas Nestel III told Philly.com that nobody, not the victims, school district, nor witnesses and transit officials, reported the crime.  

"It's an outrageous event. This is so dangerous, it's not even funny," Nestel told reporters at a news conference. "We have operating trains down there. There are passengers waiting for the train. It's horrendous."