A man critically injured when an explosion occurred this morning while he was working in a well in Ann Arbor Township is in stable condition at the hospital, fire officials said.

Meanwhile, another coworker also is in stable condition, and a third man injured has been released from the hospital, Ann Arbor Township Fire Chief Rick Ericson said this afternoon.

Police are not releasing names of the victims until each of their families have been notified. The two in stable condition were admitted to the University of Michigan Hospital, and it's not clear how long they will be hospitalized, officials said.

The explosion occurred about 8 a.m. in the 1800 block of Dixboro Road when the men, who were refurbishing a utility lift station, attempted to relight a heater that had gone out, Ericson said. They did not realize a propane tank was leaking.

"They ignited the gas, the gas exploded," Ericson said.

One man was down in the well at the time of the explosion, and was taken to the hospital in critical condition, officials said. The other two men, who were outside the well at the time of the explosion, suffered burns.

Ann Arbor Township firefighters responded, and the Washtenaw County HazMat and Washtenaw County Technical Rescue teams assisted.

Ericson said at about 2 p.m. that any related road closures would end shortly, but the department would have crews there until the gas leak dissipates.

No further details were available.