BETHLEHEM, Pa. (CBS) – A sinkhole with an active gas leak forced the evacuation of about 20 homes in Bethlehem.

Chopper 3 was over Hamilton and Elm Streets where a newspaper deliveryman discovered the large sinkhole around 3:30 Wednesday morning.

Evacuees were being housed at nearby middle school while crews repaired the gas leak.

Authorities say there were still structural concerns about the sinkhole. All but one of the evacuated homes have been allowed to return.

Officials remain on the scene.