ANN ARBOR TOWNSHIP, Mich. (AP) -- The Washtenaw County sheriff's department says leaking gas exploded in a sewer drain, injuring three workers.
WDIV-TV and WWJ-AM say the blast happened about 8 a.m. in Ann Arbor Township, near Ann Arbor.
WDIV says one of the injured men was treated at a hospital and released, while the other two remain hospitalized.
WXYZ-TV says the three were upgrading a pumping station. It says they poured concrete and were using heaters to dry it when a leaking propane tank exploded.