One construction worker died and at least 12 others were injured in an explosion Tuesday afternoon in a building under construction at the rear of the Coryell Memorial Healthcare System in Gatesville, officials confirmed during a news conference Tuesday evening.

No patients at the hospital at 1507 West Main St. were hurt, officials said.

Initially the Gatesville hospital said just four workers were injured.

Damage is extensive.

One top county official said it could take weeks or even months to reopen the hospital fully.

Crews continued to search through the rubble of the building Tuesday evening to ensure that all the workers were accounted for.

Two of the most seriously injured victims were taken to Parkland Memorial Hospital in Dallas, the officials said Tuesday evening.

Two other area hospitals, however, report receiving a total of 13 patients, which would raise the total number injured to 15.

There was no immediately explanation for the discrepancy.

Nine victims were taken to Scott & White Medical Center in Temple, one of them in very critical condition with blast injuries and burns, spokesman Deke Jones said.

That patient was immediately taken into surgery.

Six others in critical condition were stabilized and will be transferred to burn centers in Austin and Houston.

Two others suffered less serious injuries.

Four others were taken to Baylor Scott & White Hillcrest Medical Center in Waco with less serious injuries, Jones said.

Families who think loved ones were injured may call the Temple hospital at 1-888-394-4947 and the Waco hospital at (254) 202-2000.

The Scott & White Blood Center extended its hours until 8 p.m. Tuesday because of the incident.

Investigators from the Texas State Fire Marshal's Office were en route to Gatesville Tuesday evening.

Investigators from the Occupational Health and Safety Administration will also review the explosion and the damage.

County officials have been in contact with the Texas governor’s office, and representatives of Texas Sen. John Cornyn and U.S. Rep. John Williams, County Judge John Firth said Tuesday evening.

Hospital officials asked for the community's prayers.

Power was knocked out in the west side of the city and the hospital was still without power early Tuesday evening.

The 12 current patients from the 25-bed Gatesville hospital were evacuated to other facilities including Goodall Witcher Hospital in Clifton, several nurses said

The Oaks at Coryell and the Meadows near the Gatesville hospital, both of which are nursing facilities, were also evacuated.

The evacuated residents were taken to the First United Methodist Church, a church spokeswoman said.

The Gatesville ISD provided school buses to transport the nursing home residents, Gatesville Superintendent Eric Penrod said.

The hospital called in off-duty personnel to help, spokeswoman Carly Latham said.

Hospital are helping patients contact loved ones, she said.

Firefighters were sent shortly after 2:20 p.m. Tuesday to the hospital at 1507 West Main St.

Initial reports indicated the explosion occurred in a building under construction behind the existing facility that will house a boiler and chillers.

One witness said a generator exploded and officials said a natural gas line may have been involved.

Cellphone video showed a cloud of black smoke rising from the grounds of the hospital after the explosion as the first fire crews arrived.

Power was out in downtown Gatesville and at the Coryell County Courthouse and some traffic lights were dark.