Update: 9:20 a.m. - BRACE Industrial has reported that BRACE employee Antonio Navarrete has died from injuries suffered during a industrial accident at Tampa Electric's Big Bend power plant on June 29. 

"Our heartfelt prayers and sympathy are extended to his family and friends as we keep our primary focus on supporting our employees and their families during this difficult time," Chris Jones, Vice President, said. 

Antonio Navarrete's mother sent in this photo of her son. 

Original Report: Tampa Electric and federal officials are trying to determine the cause of Thursday's industrial accident that left two people dead and four others injured at the TECO power plant in Apollo Beach. 

The Occupational Safety and Health Administration announced Friday morning it has officially opened an investigation into the accident.

TECO officials have not released much information but said the accident was caused by spillage from a slag tank at the Big Bend power plant just before 4:30 p.m. Thursday.

The tank is located at the bottom of one of the power plant stacks. A slag is basically what's left over from producing power from coal. 

"What happens is you burn coal and those burned bits of coal fall into this slag tank which contains water," said TECO spokesperson Cherie Jacobs. "It cools off those pieces and it makes them crystallize." 

Routine maintenance on the slag tank was being conducted when the accident happened. 

Two people died at the scene, she said. Two were airlifted to Tampa General Hospital, and two others were taken by ground to Tampa General. They suffered severe burn injuries.

Officials released the names of the victims Friday afternoon. A contractor who died has been identified as Christopher Irvin, 40. A longtime TECO employee who died is not being identified at this time due to a request from the family. The four who suffered life-threatening injuries have been identified as Gary Marine Jr., 32, Antonio Navarrete, 21, Frank Lee Jones, 55, and Armando J Perez, 56. 

TECO announced the situation was under control about two hours after the incident and that there was no threat to the public. 

Family, former colleagues react

Less than a day later, family and friends of those lost were still devastated by what had occurred.

"I knew all those guys," said Steve Chamberland. "I worked with Frank [Lee Jones] and I worked with Chris [Irvin]. So I used to work with them and I know their work ethic. The hardest workers they got is those two guys."

The four men who suffered life-threatening injuries, along with the deceased Christopher Irvin, all worked for Gaffin Industrial, a contractor for TECO. Chamberland said Jones is the best at his job, which made the fact that this happened surprising.

"[Jones] is the guy," said Chamberland. "He’s the guy Gaffin would call if there was a tough job -- Frank wouldn’t do anything but the tough jobs. And everyone at TECO would ask, ‘Frank’s coming right?’ because they knew what he did."

Meanwhile TECO CEO Gordon Gillette spoke about the employee they lost in the accident.

"He worked at TECO for decades," said Gillette. "In fact, he was going to be celebrating his 35th work anniversary with TECO. He worked at TECO as a senior plant operator, he was well respected, and well liked by all of his fellow team members."

The family of that TECO employee has asked that we not identify him publicly, so that they can mourn in peace.

Union challenges use of contractors to increase profits

IBEW Local 108, the local chapter of the International Brotherhood of Electrical Workers, issued the following statement regarding the accident at Big Bend Power Station on June 29, 2017.

"IBEW Local 108 expresses our sincere condolences to the families of those who have lost their lives in this tragic accident. The local hopes that those that were injured have a full and speedy recovery.

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.

IBEW Local 108 has always  been concerned and focused on employee safety. 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. This will take cooperation, understanding, and effort from all parties. It can't be one sided."

Previous accidents

The incident occurred at the Big Bend Station, one of three TECO power plants and the largest. It runs on coal.

Thursday's incident comes almost two decades after a deadly explosion at TECO's Gannon power plant. That happened on April 8, 1999, with three people killed and 50 more injured.

Hydrogen contained inside the 375-megawatt generator exploded when the access cover was prematurely opened during a maintenance outage, Tampa Electric said the next day.

TECO was fined $25,200.

In July 2014, a contractor died when he slipped and fell while working at the plant. He fell through a grate on a catwalk.