GATESVILLE, Texas (CBSDFW.COM) – Emergency crews responded to a large explosion that happened at Coryell Memorial Hospital in Gatesville, Texas approximately 40 miles west of Waco.

It happened around 2:15 p.m. Tuesday at a construction site near the back of the hospital.  Hospital officials said a boiler room under construction or a gas line might have been involved.  Investigators with the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) were on the scene Tuesday evening.

Authorities confirmed around 5:45 p.m. an injured construction worker, who had been in critical condition, had died.

Twelve other people, also construction workers, were injured and two were taken to the burn center at Parkland Hospital in Dallas. Nine of the injured were taken to Baylor Scott & White Hospital in Temple. A doctor there, Justin Regner, said, “The majority of the victims had burns essentially of the entire face, ears, nose, mouth area.  Many of them had complete burns of their entire hands — both in the front and the back.  It was fairly impressive how close these individuals were to the heat.”

Power is out at the hospital and all patients have been transferred to other medical facilities.

A nursing home near the hospital has also been evacuated.

Sue Eckhart shot video of the thick, black smoke while driving by slowly and posted it on Facebook.

Brody Bertolini, a welder working next door at Kalyn Siebert, said he heard the explosion and then the power went out. They felt the concussion from the explosion.

“I looked up and everything was falling apart,” said Bertolini. “We had some lights on still but a lot of lights got knocked down.”

Coryell Memorial marketing and public relations director, Carly Latham, told Waco CBS affiliate KWTX-TV during live news coverage, that nurses followed the hospital’s disaster plan and started transferring patients out to other facilities.

KWTX viewers near the site of the explosion sent photos of the destruction.

Hospital explosion in Gatesville (KWTX viewer)

Hospital explosion in Gatesville (credit: Cody Self)

There were no doctors or patients injured in the explosion — which was in an area under construction.

Early reports indicated the explosion happened in an area where the hospital is being expanded. 

In addition to the hospital, power was out in downtown Gatesville and at the Coryell County Courthouse and some traffic lights were dark Tuesday evening.

A spokesman for the Texas-New Mexico Power Company says the explosion knocked out power for a large portion of the city but it was mostly restored a few hours later.

“I was on Levita Road picking up my dogs when I heard this loud noise and by the time I got up to Memorial Drive there were all kinds of police and fire trucks headed that way,” Gatesville attorney Tanya Place said.

She lives on Memorial Drive a short distance from Coryell Memorial Hospital.

“There’s a lot of smoke, a lot of smoke,” she said.

Tyler Ayers was working on the construction site when the explosion happened.

“I got hit in the head by a light fixture, but I’m okay,” he said. “There was an electrical generator on the other side of the building and it just blew up and scattered stuff all over the place.”

Ayers said there were others hurt but not too many. “We just got everybody we could out of the building.”

Ground was broken in November 2016 for a major renovation and expansion at the hospital.

The 117,000-square foot project includes new operating rooms, a new 25-bed hospital wing, administration offices, a 16-bed rehabilitation facility and a new central plant that houses chillers and boilers.

An Oncor spokesperson in Dallas confirms their service territory runs close by, and they do serve mutual aid. But so far their assistance has not been requested.

MedStar was monitoring the situation as well.

Flower Mound’s ambulance bus (AMBUS) was on a training assignment not far from the hospital and was rerouted to the scene after the explosion. First responders from Ellis County are also assisting emergency crews.