Spirits "aren't very high" inside the U.S. Steel Clairton plant one day after an explosion killed two people and injured at least 10, a steelworker said on Tuesday. 

Workers returned to U.S. Steel Clairton Coke Works on Tuesday morning, the first day since the losses of 39-year-old Timothy Quinn and a second employee.

"It's a little bit of shock. For the most part, most of us are still just working," said JoJo Burgess, who works at the plant and is the mayor of Washington. 

"Spirits aren't very high because a lot of people lost friends, coworkers. It's affected a lot of people," he added.

KDKA talked to Burgess before he clocked in for a double shift at the plant on Tuesday.

"The last time I heard a boom like that was in Desert Storm," he said. 

KDKA's Jennifer Borrasso asked, "Did the building shake?"

"Everything shook. It was loud. It was loud, and it shook. We knew it was something bad. So, looked out and seen the smoke, came in and called emergency services."

Burgess said he was sitting in the monitoring room, doing paperwork about 200 yards away, when he heard the explosion. He then ran out to see what happened. 

"Trying to make sense of what's going on," Burgess said. "I know a lot of people are trying to see what's going on with the investigation to see what happened."

He has worked at the plant for six years. He now works with the chemical recovery department. 

"We know there are some dangers that occur with that," Burgess said. "We work around heavy equipment. We work around a lot of materials that are dangerous, which we know how to take the proper precautions when dealing with those things."

While the investigation continues and answers come out, Burgess hopes his injured coworkers get better.

"Come back just as strong as they were before this incident happened," he said. "That they are able to continue with their normal lives."