Los Angeles ? A gunman killed three apparent relatives and a veteran SWAT officer and wounded another officer before police shot him to death Thursday in a home that erupted in flames during a long standoff. A woman escaped near the end of the siege.

Two other SWAT officers received minor fragment wounds in a barrage of gunfire, police Chief William Bratton said. He said the gunman had a handgun and a shotgun.

There was no immediate explanation of what triggered the bloodbath in the modest San Fernando Valley home, leading to the first line-of-duty death in the 41 years of the Los Angeles Police Department’s elite SWAT team.

The gunman was killed about 11 hours after barricading himself in the house and telling police in a 911 call he had killed three relatives, police said.