GATESVILLE, Texas (KXAN) — Federal agencies are working with local authorities in Gatesville to determine what caused the explosion at a construction site that killed one and injured 15 others. 

The explosion happened around 2:30 p.m. Tuesday at the rear of the Coryell Memorial Hospital, where crews were working to complete an expansion to the facility. Those who were injured were construction crew members. Police identified the man who died as Michael Bruggman, 44, of Rogers, Texas. 

Authorities said 15 other men were injured during the explosion and sent to hospitals in Austin, Dallas and San Antonio. They suffered severe burns, doctors said. City leaders expressed their support to these victims and their families. 

“We’ll continue to pray unceasingly for the speedy recovery of those injured and pray for the comfort of the family of the man that was lost,” Gatesville Mayor Gary Chumley said during a news conference. 

The hospital and emergency room will remain closed until a team of engineers determine the extent of the damage to the facilities, according to Coryell Memorial Health Systems CEO David Byrom. 

“I think that in a shorter time frame, I’m praying for that, that we’ll have our existing facility back open and hopefully be operating as we were the day before yesterday,” Byrom said, adding, “and then focusing on completing that construction.” 

Police Chief Nathan Gohlke said the state fire marshal’s office is now investigating the cause of the blast.

His officers, however, helped survey the debris field and assess damage to other buildings. They’re also asking anyone who has video or pictures of the explosion to contact police so that they can use it to further the investigation. 

While no patients or staff were injured, due to the damage of the building the patients had to be evacuated and relocated. All critical care patients are currently at other facilities. 

The Coryell Community Church is currently being used as a staging area for the employees of the Coryell Memorial Healthcare System. Pastor Daniel Crowther said about 40 elderly people evacuated to his church shortly after the explosion Tuesday. 

“When you see people in need, we know that it’s not heaven yet,” Crowther said, “but we want to do whatever we can to make it look a little more like that.” 

Coryell County Sheriff Scott Williams commended the doctors, nurses, hospital staff members and many others who ran to help Tuesday, while flames still towered 30 to 40 feet above them. 

“The danger level was very high for quite some time,” Sheriff Williams said. “Not a single person — hospital staff, law enforcement, [fire department], citizens — nobody wavered. They ran straight into the threat and saved lives.”