NEW RICHMOND, Ohio (AP) _ A 280-foot smokestack that cracked in the cold weather toppled into the Ohio River with pinpoint accuracy early today when explosive charges were set off at its base.

River barge traffic, which was halted two days ago for fear the stack would fall on its own, resumed about half an hour after the structure was dropped. Crews planned to begin removing debris from the water.

A spokesman for the Cincinnati Gas & Electric Co. said the steel-and-brick emission stack fell in one piece and hit the water with a huge splash exactly where planned without hitting any land.

``It went just perfectly,'' said CG&E spokesman Steve Brash. ``The stack lifted, made a slight turn and came down right into the river.''

A 50-foot-long, 1-foot-wide crack developed in the smokestack Sunday because of recent weather extremes, including subzero cold, the utility said.

CG&E had closed the station for fear the stack would fall on it. Brash said the utility planed to have it back at full operation today.