The call came in reporting a microwave fire already extinguished, but the incident escalated quickly to a second alarm after firefighters found flames licking up the walls toward the attic of the single-family home on Elm Street.

That was the scene Friday night in Concord, where the Fire Department, with mutual aid from Acton, Bedford, Lincoln, Maynard and Sudbury went to work on a house fire on near the Acton line.

The call came in at 8:14 p.m., according to CFD, and the fire was largely knocked down within the next hour or so, and companies readied to clear and start an investigation by 10 p.m.

Three chiefs—from Bedford, Lincoln and Concord—were on the scene, along with dozens of firefighters and several apparatus. Local and state police shut down the stretch of Route 2A from the Concord Rotary on Route 2 up to the intersection with Wetherbee Street in Acton.

There were no reported injuries through about 10 p.m., and fire officials said what complicated this operation was the way the fire progressed up through the wall, which forced firefighters to open the walls and roof to combat the blaze.

“It’s very labor intensive,” Concord Fire Chief Mark Cotreau said on the scene, “And because of the work we had to do here, we struck a second alarm.”

The extent of the damage to the home was unclear as of Friday night, but firefighters on the scene said it did not appear to be a total loss.