The five-alarm fire that consumed an Edgewater, NJ apartment complex on Wednesday night was called "accidental" by authorities. The accident in question sounds particularly dumb: Workers doing plumbing maintenance work with a blowtorch started the fire... and called their supervisor before calling 911.

NJ.com reports:

In a press briefing attended by Gov. Chris Christie Thursday afternoon, Edgewater Police Chief William Skidmore said Avalon maintenance workers were using a blowtorch to perform plumbing repairs in a first-floor apartment at about 4 p.m. when the fire began inside a wall. Instead of immediately calling 911, the workers first phoned their supervisor, leading to a 15-minute delay in the emergency response, Skidmore said. That decision, the chief said, “certainly didn’t help” in stopping the fire’s spread. "It was mostly a big contributor because it was a delay in the response of the fire department," he said. Asked if the delay opened the workers to criminal liability, Skidmore said it did not, terming the fire a “tragic accident.”

The "tragic accident" was epic—of the 408 apartments at the Avalon Edgewater, 240 were destroyed, leaving at least 500 people homeless. The complex did have sprinklers, but they weren't meant to completely douse a fire—500 firefighters from neighboring NJ towns and NYC helped to fight the blaze.

The building was built of "lightweight" wood which was a big factor. The Bergen Record reports, "Firefighters and construction-industry representatives have fought for years over whether there should be stricter regulations on the building method."

“The occupants of this building probably didn’t realize they were basically living in the middle of a lumberyard,” said Jack J. Murphy, a past president of the Bergen County Fire Chiefs Association who teaches fire safety at the John Jay College of Criminal Justice. “The only saving grace was that this didn’t happen at 2 a.m.” The truss style of roof framing allows sections to be built of lighter lumber on the ground, then hoisted into place. The method is generally considered to be faster and less expensive to install.

Fire officials believe that if the structure were made of concrete and cinder block, the fire wouldn't have been as extensive—and "fire chiefs interviewed on Thursday said lightweight construction forces firefighters to work in dangerous conditions."

A huge cleanup is required to clear the site. Here's information on how to help residents (donations, clothing, etc.).