Investigators said two large groups of teenagers - as many as 40 - were fighting just before 8 p.m. Friday at Murdy Park at Goldenwest Street and Warner Avenue. A woman attempted to break up the melee, but some of the teenagers turned on the woman, prompting her 25-year-old boyfriend to intervene.
A group of five to 10 teens chased the man across the street and into a laundromat. Police said at least four of them attacked him using their skateboards as weapons, while other teens captured the crime on camera and later posted it on Facebook.
When police officers arrived, the teens allegedly ran in multiple directions. Of the seven detained, four of them were booked for attempted murder at Orange County Juvenile Hall.
The victim, whose identity was not released, was taken to UCI Medical Center, where he underwent emergency surgery. He was listed in critical condition.
"It was a very brutal attack, we have no reason to believe that the victim had anything to do with these groups before he tried to intervene in this altercation," said Lt. Bo Svendsbo of the Huntington Beach Police Department.
The four teens were all on criminal probation for other crimes. They were not identified because they are minors.
Miguel Espinoza, a friend of the victim, said he was in disbelief over the brutal attack.
"This guy is a genuine, stand-up type of person. What could you possibly do to someone to have them want to kill you with a skateboard?" Espinoza said.
In addition to the video investigators found online, they were also reviewing surveillance cameras from nearby businesses.