OKLAHOMA CITY (AP) - A second man who was injured in an explosion at a southern Oklahoma oil refinery has died.

A spokesman at the University of Oklahoma Medical Center in Oklahoma City says Russell Mann of Davis died Tuesday.

Mann was injured and Billy Smith of Pauls Valley was killed in the Sept. 28 explosion of a boiler at Wynnewood Refining Co., owned by CVR Energy Inc. of Sugar Land, Texas.

CVR officials have said the explosion occurred as the boiler was being restarted following scheduled maintenance and upkeep - a process known as a "turnaround."

The turnaround resumed the following day.

Officials with CVR and the U.S. Department of Labor - which is investigating the explosion - did not immediately return phone calls seeking comment.

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