What caused an explosion at the US Steel plant in Pennsylvania? What we know
After an explosion at a steel plant near Pittsburgh killed two and injured several others, investigators have shifted from a search-and-rescue operation to determining the cause of the blast.
All those present at the U.S. Steel Clairton Coke Works plant in Clairton, Pennsylvania, about 15 miles outside Pittsburgh, had been accounted for by the evening of Aug. 11, officials said. Two people were killed, 10 were treated for injuries in a hospital and many others were treated on the scene for more minor injures. Five of the 10 hospitalized were in "critical but stable" condition, Allegheny County Emergency Services Chief Matt Brown told reporters.
One of the victims was identified as 39-year-old Timothy Quinn, a news release from Allegheny County said.
Authorities have not yet indicated what could have caused the explosion, which was followed by other smaller explosions the morning of Aug. 11. In the hours afterward, all efforts were focused on finding the missing. The next phase in the investigation will include interviewing employees and flying in experts, officials said.
"It does bring our incident from an emergency standpoint to a close, it certainly doesn't close the incident as a whole," Brown said. "There's lots to be investigated."
Here's what we know:
What happened in the U.S. Steel plant explosion?
Emergency crews responded to a 911 call at 10:51 a.m. on Aug. 11 that there was an explosion at U.S. Steel Clairton Coke Works, the Allegheny County Emergency Services and Allegheny County Police Department said.
An initial fiery explosion was followed by secondary explosions. Photos and videos of the scene showed a large plume of dark smoke rising from the plant and firefighters battling flames.
The explosion "sounded like thunder," Zachary Buday, a construction worker who was nearby, told WTAE-TV.
"It shook my chest. It shook the building, then we saw the dark smoke rising from the steel mill," he said.
One person was initially confirmed dead, and two others were missing after the initial explosion. After an exhaustive search, another person was found deceased and the third was found and taken to a hospital with injuries.
"Multiple explosions" happened at the plant, Pennsylvania Gov. Josh Shapiro said in a post to social media. "If you’re in the area, continue to follow the instructions of local authorities."
Officials asked residents within a 1-mile radius of the plant to remain indoors.
What caused the explosion?
The probe into the cause of the explosion is underway. The initial calls to 911 indicated it happened inside a battery operating area of the plant, officials said.
The extent of the damage is not yet known, U.S. Steel spokesperson Kurt Barshick said. Barshick said part of the plant is still operable and would continue producing coke, which is used in the steel-producing process.
Who was killed? What is the condition of the injured?
Quinn was pronounced dead on the scene of the explosion at 11:24 a.m. on Aug. 11, officials said.
Authorities haven't released the identities of the other person killed.
Five of the 10 people who were treated at hospitals are in stable but critical condition, and the other five were treated and released, Brown said.
There were dozens of "walking wounded" initially treated at the scene and sent home, Kasey Reigner, spokesperson for the Allegheny County Emergency Services, previously said.
What is a coking plant?
A coking plant produces coke, a porous, carbon-rich material that is used to make steel in a blast furnace, according to the Kentucky Geological Survey. Coal is heated without oxygen to extreme temperatures, as high as over 1,000 degrees Fahrenheit, to produce coke.
The plant in Clairton is the largest coke-manufacturing facility in the United States. It operates 10 coke oven batteries.
Contributing: Melina Khan, Jorge L. Ortiz, Phaedra Trethan, Matthew Rink and Marc Ramirez, Paste BN; Reuters