HONOLULU -- The State Office Tower remained closed all Friday as damage from Thursday's gas explosion was found to be worse than expected.

Employees who routinely work in the service area of the building all agreed that if it had not happened early in the morning, someone could easily have been killed.

The explosion happened early Thursday morning as firefighters searched for the source of gas smelled by late-working employees.

The Honolulu Fire Department said officials confirmed that the building had no gas pipeline so firefighters entered assuming they were dealing with a small problem. Instead there was a steady stream of gas from a leaking 4-inch pipeline.

The gas reached explosive saturation inside a communications room.

The explosion turned heavy doors, file cabinets and an air conditioner into scrap metal, but seemed to spare delicate electronics. The room was a communications hub for three buildings.

The gas company and fire department both expressed great concern about the explosion. The State Office Tower was not hooked up to The Gas Co. system. Officials suspect it leaked through ducts and conduits into the room.

"One thought that we are looking at its seems very likely or the most likely is that somehow the gas got into our ducts, which got into our conduits, which feed into this room here," state Comptroller Russ Saito said.

In one duct, it appeared that a conduit tube was removed without new sealant going in.

The room's air conditioner was thrown outside. Despite both the explosion and a flood from fire sprinklers, there did not seem to be much damage to the communications equipment that tied together three buildings.

Repairs to the leaking gas line under Beretania Street continued until Friday afternoon and will resume Saturday.

Workers at the State Office Tower are expected to report as usual Monday morning. There is no estimate yet on the cost of the damage.

The question now is how it happened. The Gas Company and Honolulu Fire Department said they are very concerned about how gas could have migrated into the building.