GOUVERNEUR - Federal officials on Sunday began investigating an underground accident that killed a 40-year-old mine worker.

State police said the Saturday morning accident that killed Willard Paul Clewis of Gouverneur occurred while Clewis was working approximately 2,100 feet underground in a mine owned by the St. Lawrence Zinc Co.

Troopers said the victim was standing on a platform drilling into a wall when the ceiling above him collapsed, leaving him pinned under a rock that measured approximately 8 feet by 4 feet.

Company general manager Michael Lawler confirmed the fatality Saturday night.

Rescue workers said Clewis showed no signs of life when they reached him, and lifesaving measures were stopped about an hour after the collapse.

Clewis was working with Richard R. Aldridge, 20, also of Gouverneur. Troopers said Aldridge was able to jump clear of the collapse and escape serious injury. He was freed by mine rescue personnel.

Investigators from the Mine Health and Safety Administration will try to determine exactly what went wrong, and St. Lawrence County Coroner R.B. Lawrence III ordered an autopsy to be conducted Monday.

The fatal accident happened just over a year after another worker was trapped nearly 3,100 feet beneath the ground for approximately two hours in the same mine.

He was freed and treated for non-life-threatening injuries.