The Orange County Register says it happened Friday night after a woman bystander tried to break up a fight between two groups at a Huntington Beach skate park.
Police Lt. Chad Nichols says the skateboarders turned on the woman, and her boyfriend intervened and was chased to a nearby coin laundry and beaten with skateboards. He was taken to a hospital in critical condition.
Seven boys under the age of 18 were detained. Four of them were arrested on suspicion of attempted murder and were booked at Juvenile Hall.
Authorities say all four were on probation for previous crimes.