Two firefighters were sent to the hospital after battling a house fire in the  Seven Corners area of Fairfax County, Virginia, that investigators traced back to wiring.

Firefighting units from Fairfax and Arlington counties were called to a burning home in the 6100 block of Munson Hill Road at 2:19 a.m. Tuesday when a neighbor saw flames shooting through the roof.

Nobody was home when the fire broke out, the Fairfax County Fire and Rescue Department said in a news release.

Two firefighters were transported to a hospital for a checkup as the blaze was brought under control.

Investigators later determined the fire started in the attic.

Its cause was an “unspecified electrical event involving household wiring,” the fire department said.

Smoke alarms were present and working, but did not go off due to the fire being in the attic.

Damages to the home are estimated at just under $310,000.