(Reuters) - Two workers were killed and four injured in a mishap while they were performing routine maintenance on a tank at a Tampa-area coal power plant on Thursday, rescue and company officials said.
The workers were carrying out maintenance on a tank containing slag, a byproduct of coal, when the incident occurred at Tampa Electric's Big Bend Power Station in Apollo Beach, Tampa Electric and Emera Company spokeswoman Cherie Jacobs told a news conference.
"The details on how this happened, we don't know," she said.
Rescue workers received a call at about 4:20 p.m. local time about a possible explosion at the plant. They found two workers dead and four injured when they arrived, said Corey Dierdorff, a spokesman for Hillsborough County Fire Rescue.
The injured workers were taken to the hospital with life-threatening injuries, he said.
"They would be categorized as very severe," he said, according to the New York Times.
Coal produces slag when it burns, which falls into a water tank at the plant where it cools and crystallizes. The substance is then recycled to be used for sandblasting and roofing industries, Jacobs said.
The dead workers were covered in slag, which can reach temperatures higher than 1,000 degrees Fahrenheit (538 degrees Celsius), authorities told the New York Times.
Power service was not interrupted and all other workers were accounted for, Jacobs said.
(Reporting by Brendan O'Brien in Milwaukee; Editing by Paul Tait)