APOLLO BEACH (FOX 13) –ÂFire and rescue crews say two people have died and several others were injured in an industrial accident at Tampa Electric’s Big Bend power plant in Apollo Beach.

TECO’s public information officer, Cheri Jacobs said workers were performing routine maintenance on a slag tank at the time of the accident, around 4 p.m. Thursday.

Jacobs explained slag is the byproduct of burning coal, which is the primary function at the Big Bend power plant. The slag falls into a water tank and crystallizes, and is then recycled for use in the sandblasting and roofing industries.

Jacobs was unable to say what exactly caused the accident that killed the two workers and seriously injured four others but added they were trying to find out so it didn’t happen again.

The view from SkyFOX, meanwhile showed at least four fire trucks at the scene and several ambulances and other emergency vehicles.

Four patients were taken to Tampa General Hospital – two by helicopter and two by ambulance. Their injuries were said to be life-threatening and some were described as burn injuries.

TECO said an employee assistance program would be activated to help the employees and their families, as needed.

“Tampa Electric is full of long-term employees and we have long been a family,” TECO’s spokesperson, Cherie Jacobs said during a press conference Thursday. “The Tampa Electric family is in mourning. We are looking into this accident to make sure everybody has what they need.”

The stacks of the Big Bend power plant are a familiar landmark to many in the Bay Area, towering above the eastern shore of Tampa Bay. The plant is also famously home to manatees in the winter, who flock to the warm water flowing from the plant when temperatures drop.