APOLLO BEACH — It was the kind of job that workers at the Big Bend power plant do routinely, and one done countless times in the nearly 35 years that senior plant operator Michael McCort had worked at Tampa Electric.
But company executives said something went tragically wrong Thursday as McCort, 60, and at least five employees working for outside contractors tried to unplug a tank containing molten slag that can reach temperatures of more than 1,000 degrees.
Slag gushed from the tank, falling onto the workers below. The flow — "like what comes out of a volcano," one expert said — covered the floor six inches deep and 40 feet across.
McCort, of Riverview, was killed along with contractor employee Christopher Irvin, 40, of Tampa. Another four contractor employees were hospitalized with life-threatening burns or other injuries: Antonio Navarrete, 21, and Armando J. Perez, 56, both of Wimauma; and two Tampa men related by marriage, Frank Lee Jones, 55, and his stepson, Gary Marine Jr., 32.
On Friday, two investigators from the federal Occupational Safety and Health Administration were starting an investigation that could last six months. Relatives said two of the men were fighting for their lives with burns on more than three-quarters of their bodies. And Tampa Electric employees were grieving.
"Today, in addition to working with OSHA, our focus is on our team members and their families," Gordon Gillette, president and CEO of Tampa Electric, said at a news conference. "We're doing everything we can to help them. Every team member at TECO is feeling the loss today, especially our members at Big Bend Power Station."
McCort was described as well liked and well respected. On Facebook, Maria Ramirez-Reyes of Gibsonton wrote, "I'm in so much pain right now. My brother Marro Navarrete is fighting for his life. Right now he has 78 percent 3rd degrees burned on all his body."
The deadly accident occurred about 4:20 p.m. Thursday in Unit 2, a coal-fired boiler at the Big Bend plant, as workers did what is usually routine maintenance on the slag tank. Hot slag is a molten by-product created when coal is burned for electricity. Chunks of it fall into cooling tanks and the remnants, which are black and glass-like, are recycled and used in sand blasting and roofing.
Gillette said the workers were trying to unplug a blockage in the tank when hot slag rushed out onto them. Some of the workers were closer to the tank than others, he said.
"Because of the significant radius," he said, "all of those on scene were affected in some way, unfortunately."
Victims suffered burns as well as other injuries that "would be categorized as very severe," Hillsborough County Fire Rescue spokesman Corey Dierdorff said.
What exactly happened is still unclear because there were no workers present other than those killed or injured, said Gillette, who visited the site after the incident.
McCort was a Tampa Electric employee, company spokeswoman Cherie Jacobs said. The power company declined to name the contracted firm or firms working on the site.
Three of the injured workers are employed by BRACE Industrial Group, based in Houston, according to the company. It did not identify its employees, but the Tampa Bay Times learned Friday that Navarrete and Perez work there. The company said a third employee, whose name was not disclosed, was treated and released.
"We are supporting TECO's investigation into the incident and cooperating with local authorities and emergency responders," the company said in a statement. "Our primary focus is on supporting our employees and their families during this difficult time. Our thoughts and prayers are with all of the injured individuals and their families."
The Times also learned that Irvin, Marine and Jones worked for Gaffin Industrial Services in Riverview. Gaffin chief executive officer and president Dan McLeary declined to comment.
Steve Chamberland, 46 of Largo, worked for Gaffin 12 years ago but still knows Chris Irvin and Frank Lee Jones, who he said had worked for the company for 27 years.
"Both of them are probably two of the hardest workers at Gaffin," he said. "Chris was the guy that wants to work 90 hours a week and make money for his family," and when he worked as a foreman, his teams always respected him. "He would do everything he would have the guys do."
After the accident, other workers rushed in to help, Gillette said.
"There were some extraordinarily courageous efforts on the parts of the TECO team members to save the employee and our contractors," he said.
Two investigators from OSHA's Tampa office were on the scene Friday to begin talking to witnesses, examining physical evidence and considering the companies' safety records.
"They're in the preliminary stages," said Mike D'Aquino, an OSHA spokesman based in Atlanta. "This seems like it will be a pretty complex investigation."
Also participating in the investigation was the president of the International Brotherhood of Electrical Workers, AFL-CIO, Local Union 108.
"We don't know what happened," union president Steven Fountain said. Later Friday, union business manager Doug Bowden said the union expresses its condolences to the families of those killed and its wishes to those injured for a full and speedy recovery.
But, he added, "this incident could have been avoided — period. It's time to listen to the employees. It's time to stop using contractors to do 'routine maintenance' when the safety of this maintenance has been questioned by employees. It's time to stop putting profit before safety. It's time to truly put safety first. ...
"We are currently working with OSHA in their investigation, and we are determined to do all that we can to prevent this from happening again," Bowden said. "This will take cooperation, understanding and effort from all parties. It can't be one-sided."
Gillette said safety is the No. 1 priority for Tampa Electric and its corporate parent, Emera. The staff of 300 at the Big Bend plant constantly takes lessons from each other and from best practices in the industry, he said.
"We work millions of man-hours every year on very large and complicated equipment," Gillette said. "Even walking up and down stairs is a focus area of safety for us. That's what makes this so very, very difficult. We never want to have to learn in this way. We will, however, learn from this incident. But today is for us to care for our team members and their families."
High pressure in the slag tank may have caused the slag to shoot out at high speed, said Randy Barnett, a program manager at NTT, a Colorado safety training company whose clients include utilities.
As coal ashes from the bottom of the boiler drop into the slag tank, they mix with water, becoming a hard glassy silica material, he said. The high temperatures instantly turn the water to steam, creating high pressure within the enclosed tank.
"If the slag is not properly controlled, a steam explosion can result as the hot molten slag hits the much cooler water," he said. "Water, instantly flashing into steam, causes the water to expand over 1,500 times its normal volume resulting in an explosion. Such an area could be inundated with steam, flying shrapnel and molten slag."
Barnett, who has worked in both coal and nuclear power plants, said when workers are injured, it is almost always the result of either unsafe conditions or unsafe acts.
"Did something go wrong? Was it the person's actions? Were they not following procedures?" he said. "There's a lot that needs to be looked at."
Times researchers Caryn Baird and John Martin and staff writers Langston Taylor, Jon Capriel, Sara DiNatale, Caitlin Johnston, Mark Puente and Taylor Telford contributed to this report.