Norwich — Fire officials are investigating what caused a pile of railroad ties to burn for several hours Tuesday evening.

The fire encompassed more than half of a stack of creosote-treated timbers on the Providence and Worcester Railroad property between Laurel Hill Avenue and the Thames River.

Norwich Fire Chief Ken Scandariato said the fire was reported at about 6:11 p.m. and was under control by 11 p.m. Fire crews left the scene at 12:05 a.m. Wednesday.

Scandariato said that crews used 350 gallons of foam to help supress the fire. With help from the Laurel Hill Fire Department's hose tender, firefighters uncoiled 2,700 feet of hose from a hydrant on Laurel Hill Avenue to reach fire engines along the railroad tracks. It took another 400 feet of hose to reach the fire.

Rail service was halted during firefighting operations, he said.

Scandariato said Tuesday was an especially busy day as firefighters responded to 12 calls in a 14-hour period.

"We're always working," he said.