Blast, Fire Cause $200,000 Damage at Vacant High-Rise

An explosion on the roof of a vacant 12-story bank building late Tuesday night that shook nearby residents and triggered a fire caused an estimated $200,000 damage, officials said Wednesday.

Witnesses reported a loud boom about 11 p.m. and then flames visible for miles from the top of the Union Bank building at 600 S. Main St.

The 12-story building was vacant because it was being renovated, said Battalion Chief Dick Dittberner of the Orange Fire Department.

Although investigators Wednesday had not determined the cause of the fire, Dittberner said a propane tank on the roof might have been ignited by a tar kettle left on to prevent the tar from hardening overnight.

“The majority of the fire was located around the tar pool area, but we are not ruling out arson yet,” Dittberner said.

More than 49 firefighters from Orange, Santa Ana and Tustin battled the blaze and were able to control it within 30 minutes, Dittberner said. No one was injured.

The flames were first spotted by a Costa Mesa police helicopter crew several miles away. The fire forced emergency crews to briefly close the westbound lanes of the Garden Grove Freeway and nearby residential streets, an area that included St. Joseph’s Hospital and Children’s Hospital of Orange County.

The bank building is owned by General Motors Trust Fund.

When renovations are complete this summer, one of the new tenants will be the Orange County Transportation Authority, agency spokeswoman Elaine Beno said. The agency hopes to consolidate 284 employees who are now working in five different locations.