Officials have confirmed that one construction worker died and 12 others were injured in the explosion.
Police have stated that they are responding to a "major emergency" at the hospital, AlboeNews reported Tuesday.
The hospital and nearby nursing facilities have been evacuated. Patients are being transferred to a nearby hospital in Hamilton, Texas. At least 12 people have been transported to area hospitals, Gatesville police confirmed Tuesday afternoon.
"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, who lives nearby, told CBS News. "There's a lot of smoke."
"I got hit in the head by a light fixture, but I'm okay," Tyler Ayers, who was near the site of the explosion, told KWTX-TV. "There was an electrical generator on the other side of the building and it just blew up and scattered stuff all over the place."
There are also reports of a power outage in the surrounding area.
Coryell Memorial Hospital provides several health services, including a level IV trauma center emergency room, more than 30 primary and specialty care providers, an advanced wound care center, outpatient rehabilitation center and a nursing facility with long-term care and inpatient rehabilitation, KCEN-TV reported. The hospital began renovations in November 2016.