Two workers who were stuck in an air shaft overnight above the Liberty Tunnels have been rescued.

The men entered the 3- by 8-foot air shaft about 10:30 p.m. and became stuck when their mechanical lift lost power about 3:30 a.m. Emergency crews used harnesses to lift the men from shaft around 5 a.m. An earlier effort to lower a generator to the men failed.

The workers had oxygen and were not in danger, a PennDOT spokesman said. But they did have to suffer through 20-degree temperatures.

The shaft leads to a fan housing on top of Mount Washington that draws vehicle exhaust from the tunnel. The men were stuck about 60 feet from the top of the shaft.

The workers were not identified.