EAGLEVILLE, Pa. (AP) — Two workers were cleaning an empty water tower Wednesday outside Philadelphia when scaffolding collapsed under them, sending one man plummeting to his death and leaving another hanging for three hours in a safety harness until he could be rescued.

Three men from Corrosion Control Corp., based in Pedricktown, N.J., were working inside the 100-foot-tall tower when an apparent equipment malfunction occurred shortly after 11 a.m., Lower Providence Police Chief Francis "Bud" Carroll said.

One man fell roughly 50 feet to his death, while the other dropped only partway and dangled from a harness. It took a rescuer more than three hours to free the trapped worker by going through the top of the tower, descending and attaching a second safety harness so they could be lowered together and leave through a small exit at ground level.

The survivor was being checked out at a hospital. No word was immediately released on his condition.

"He was talking to us from the onset. That is why this was not a rushed operation," Lower Providence Fire Chief Bryan McFarland said. "We took our time and put as much safety into (the rescue) as we could."

A third man was working inside the tank on ground level and was not hurt, Carroll said.

Carroll said the crew had been hired by Audubon Water Co. to clean the inside of the tank, in a residential neighborhood in Lower Providence Township, about 25 miles northwest of Philadelphia.

The U.S. Occupational Safety and Health Administration will investigate, Montgomery County Coroner Walter Hofman said.