Four teenagers are charged in what Rochester Police called a “completely unprovoked” attack on a man that was streamed live on Facebook.

It happened in downtown Rochester at the corner of Main Street and Clinton Avenue around 3:30 p.m. Wednesday.

Police say the victim suffered head trauma and was rushed to the hospital with serious, but non-life threatening injuries.

Alleged Gang Assault in Rochester is streamed live on Facebook. Interim Police Chief Mark Simmons says this video is difficult to watch. Four suspects are under arrest. Police thank the citizens who called 911 as they watched this crime unfold. @SPECNewsROC pic.twitter.com/q3Hj1QIWs4 — Wendy Wright (@WendyWrightTV) February 22, 2019

All four teens are charged with gang assault in the first degree, a Class B violent felony that can bring a five to 25 year sentence.

Two of the suspects are 16 years old and appeared in Youth Part court. Spectrum News is not reporting their names. The other two suspects are 17-year-old Xavier Lopez and 19-year-old Brandon Purdie, both of Rochester. Both pleaded not guilty in city court.

Officers credit a citizen who saw the live feed with alerting them to the assault.

"We’ve been working very hard over the last few years to build a relationship with our community so that they have faith and confidence in the police department that if they pick up the phone and call 911, officers are going to respond in a timely manner and be responsive and go and get the job done to make sure that our community remains safe,” said Interim Police Chief Mark Simmons.

Investigators say additional charges and arrests are possible as they review a large amount of video cameras from that intersection.