Firefighters responded to reports of a “gas smell” at the center shortly after 0800 ET (1200 GMT), NBC reported.
Within seconds of their arrival, the center exploded. It isn’t clear at this time what caused the explosion, Maine Governor Janet Mills said.
Four firefighters, an emergency medical technician and a maintenance worker with facility, were believed to have been injured in the explosion.
(Production: Deborah Gembara)