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Just over a year ago, the church was on fire, and on Wednesday, another fire broke out just before 11 p.m.
The Los Angeles City Fire Department has determined the cause of the fire as electrical problem near a water heater in the back of the church.
The repairs from the last fire had just been complete, and the church was getting ready to move back into the office area.
There was a youth ministry meeting that had just ended. Everyone was in the parking lot when they noticed smoke coming out of the church buildings.
"I was in bed and I heard the sirens, and I just came out and seen the smoke," said church staff member Martha Montiel.
More than 150 L.A. City Firefighters fought the blaze for about an hour.
"What's tragic about this is a year ago we had a fire in the offices, so it's like here we go again, and it's unbelievable," said Don Ezell, pastor of Harbor Christian Church.
No one was injured, and authorities have not determined a damage estimate. Last year's fire repairs cost about $1 million, and the pastor said Wednesday night's fire was much more extensive.
Firefighters were able to keep flames away from the sanctuary, and once the cleanup is done, authorities are optimistic that the church will be able to have service on Sunday.
The cause of the fire is under investigation.