WOODBRIDGE - A tiny chink in an armored electrical cable was most likely to blame for an October fire that destroyed the second story of the historic Woodbridge Firehouse, a state fire inspector's report states.

The Oct. 7 fire destroyed the second floor and part of the roof, which will be repaired, First Selectman Ed Sheehy said.

While some firefighters don't see the point in repairing a cramped, 69-year-old firehouse while the town is trying to convince voters to approve a new $6 million firehouse planned for Center Road, leaving the second floor gutted would leave the town with an unusable building.

"(A new firehouse) is going to be a two-year process. In the meantime, you have to have a firehouse," Sheehy said, adding that once a new firehouse is built, the old one will be converted to public use.

The new 20,000-square-foot firehouse is estimated to cost far more than the town is expected to receive as reimbursement from its insurance company.

An architect hired last year is drafting a design package that will help pinpoint the actual cost, which could exceed $6 million, and the town could be voting on the project in the spring.

The state fire inspector's supplemental report said the fire appeared to start in an attic next to a cupola containing the firehouse's main siren.

It appears that a cracked armored sheath surrounding an electrical cable sparked the blaze. The crack was only an eighth-of-an-inch wide. The town hired architect Silver Petrucelli & Associates of Hamden for $100,000 last year to design the new firehouse, and hired construction manager Newfield Construction of Hartford about a month ago. The committee should receive a design packet in the next two or three months, said Joseph Calistro, who chairs the town's new fire station committee. The project would be up for a referendum soon after that.

"Bumper to bumper" is how Woodbridge Fire Chief Andrew Esposito described the cramped conditions in the damaged but usable firehouse. The Board of Selectmen also approved buying a $484,000, 30-foot rescue truck in January that should be delivered next year. Esposito said he's going to have to leave fire apparatus parked outside.

If the referendum is approved, the new project will raise taxes. But Calistro, whose committee has talked about building a new firehouse for almost 10 years, said it's badly needed. "At some point, you have to bite the bullet," Calistro said. "We really need it. … It took the town 13 years to get a new library."