Contractors working inside a vacant building cut through a gas line, flooding the building with natural gas and creating the potential for a catastrophic explosion midday Monday, according to West Caldwell fire officials.

The West Caldwell Fire Department and PSE&G reported to the scene just before noon and worked briskly to avert an explosion at a former medical office which is currently under construction on the corner of Bloomfield and Lougheed avenues.

Gas service was cut off to the one-story stucco building and surrounding buildings, including garden apartments and a medical complex, were evacuated. Bloomfield Avenue traffic was shut down in both directions and traffic was diverted for about an hour until the building was cleared of gas.

"The combination of the on rushing air into the building and the build up of natural gas inside created an extremely dangerous condition for a possible building explosion,” West Caldwell Fire Chief Jim Alvine stated in a release Tuesday.

Adding to the potential danger was an air compressor in the building which could have acted as an ignition source, Alvine said.

"There was an air compressor inside the building for the use of tools,” he said. “If that compressor motor operated, that would have been the ignition source for what could have been a catastrophic explosion."   

Contractors working inside the building cut through a 1 1/2" gas line, causing natural gas to flow freely into the building. Firemen could not safely enter the building due to the high levels of gas inside and the open windows.