WASHINGTON, Sept. 16 (Xinhua) -- One firefighter was killed and several others were injured in an explosion at a building in Farmington in the northeast U.S. state of Maine on Monday morning, according to officials and local media reports.

The explosion occurred in the morning when firefighters were responding to a smell of propane at a nonprofit site for people with disabilities in Farmington, BNO News reported.

Maine Governor Janet Mills tweeted that she is monitoring the situation and urged residents to avoid the area.

The state's Fire Marshal's Office will investigate the cause and origin of the explosion, she said.

Footage and photos from the scene showed that the building was completely destroyed.

The building is a LEAP facility, which provides support to people with developmental, cognitive and intellectual disabilities.

Farmington is about 50 kilometers northwest of Augusta, Maine's capital.