The twin blimp hangars in Tustin have stood tall since World War II, a home port to enormous zeppelins and fleets of helicopters that were being readied for war.
But age is finally starting to catch up.
The roof of one of the 17-story structures collapsed last week, damaging an experimental airship and raising new questions about the future of the historic buildings that stand as reminders of a long-ago era.
The damaged hangar, the best preserved of the two, is slated to be handed over to Orange County as the centerpiece of a proposed 85-acre regional park. Now county leaders say they are worried about inheriting a building that could cost millions to maintain or refurbish and no longer has a practical use.
"I don't want six months to go by and suddenly the Navy says, 'Take it or leave it as is,' " said Supervisor Todd Spitzer. "I don't want to be put in that position."
County attorneys are reviewing conveyance documents to determine who will have to repair the hangar if plans for the park move forward.
"I want to do everything we can to save it, but if it's a $500,000 or $1-million repair we're going to have to have some serious discussions," Spitzer said after the hangar's roof collapsed. "We're not a bottomless pit."
But repair and maintenance costs are premature at the moment, said Anthony Megliola, the base closure manager for the former Marine Corps Air Station in Tustin.
The U.S. Department of the Navy is sending a structural engineer to investigate the roof collapse and assess the hangar's integrity, which was red-tagged after the accident. Megliola said annual maintenance costs have averaged $160,000 over the last five years.
County officials estimate that it would cost about $20 million to refurbish either one of the hangars. The Navy is responsible for maintenance and inspection costs.
Megliola said it's too early to tell whether the Navy will be required to make any repairs before handing the hangar over to Orange County, and the Navy hasn't determined whether it'll pay for the damage to the $35-million airship.
Ever since the retired Marine Corps Air Station was transferred to Tustin in 1991, ideas for how it might be put back to use have ranged from the practical to the extreme.
One plan called for converting it into a skiing attraction, with two 145-foot slopes. Another suggested it be used as an arboretum while others proposed a 400-acre medieval Poland theme park complete with a wall and moat to be built on the surrounding grounds.
The hangars were built mostly from Oregon Douglas fir — an available resource in a time of extreme rationing during World War II — over a ninth-month span in 1943. The 2 million board feet of wood were treated with metallic salts as a fire retardant.
At 17 stories tall, 1,000 feet long and 300 feet wide, the hangars are two of the world's largest free-standing wooden structures. Both are listed in the Register of National Historic Places.
The blimps housed there were used as sentries during WWII, armed with machine guns, bombs and charges to fend off submarines. The base was decommissioned in 1949 and reactivated in 1951 in response to the Korean conflict, according to historical county records. It became the country's first military airfield dedicated solely to helicopter operations, which were being heavily used to move troops and supplies.
The base was used again during the
The county had been toying with the idea for a regional park for years and petitioned the federal government for the property, including the north hangar.
"Our assumption all along has been that the hangar would be part of the regional park," said Marisa O'Neil, spokeswoman for OC Parks, which manages wilderness areas, regional parks and historical sites in the county.
Under current plans, the hangar was to essentially remain empty but could be leased out for filming and large events. County supervisors are expected to make a decision on the park plans in 2014, with a tentative opening date in 2016.
Other California hangars are undergoing or have undergone similar transitions, said Peter Westwick, author of "Blue Sky Metropolis: The Aerospace Century in Southern California."
He cited the Howard Hughes complex in Playa Vista, which included the hangar where Hughes' "Spruce Goose" — a wooden plane with a 320-foot wingspan — was built. As part of a $50-million renovation, the seven-story building has multiple soundstages for television and films.
"The question now is what do we do with these giant structures now that their original purpose has disappeared," Westwick said.