Portland police officer David Bond said one firefighter was taken to Hartford Hospital and may be transferred to the burn center at Bridgeport Hospital. He said other the firefighter was taken to Middlesex Hospital where he was treated and released with minor injuries.
Bond said the two firefighters were checking the building for anyone left inside when the tank, which had been leaking propane, exploded.
Names of the firefighters and their departments were not released. No injuries were reported immediately among residents of the building.
Officials say firefighters were at the scene battling the blaze.
A large section of the house has collapsed.
No other information was available.