Story highlights Hospital is told to anticipate 100 injured, official says

The explosion occurs at a fertilizer plant some 18 miles north of Waco, KWTX reports

A man says he saw smoke then, a few minutes later, heard a massive explosion

A massive explosion at a fertilizer plant in the small Texas town of West left at least two people dead, sent dozens more seeking medical attention and prompted a widescale evacuation in the community of 2,600 people.

Fire officials fear that the number of casualties could rise much higher.

The blast took place at the West Fertilizer Plant, about 18 miles north of Waco. It sent a massive fireball into the sky

And the danger may not be over.

Residents are being evacuated because officials are worried that another tank at the facility might explode.

State troopers in gas masks were scene rushing to the area shortly after the blast,

Shortly after the explosion, more than 60 patients streamed into Hillcrest Hospital in Waco, suffering from "blast injuries, orthopedic injuries (and) a lot of lacerations," said hospital CEO Glenn Robinson.

While some of the injuries are minor, others are "quite serious," he said.

At least six helicopters are going to fly out those who are injured, Robinson said. Others are being transported by ambulance, and some are getting to the hospital by car, he added.

Two other hospitals in the region were also assisting.

As many scrambled to assist the injured, another danger seemed to emerge Wednesday night.

"What we are hearing is that there is one fertilizer tank that is still intact at the plant, and there are evacuations in place to make sure everyone gets away from the area safely in case of another explosion," said Ben Stratmann, a spokesman for Texas State Sen. Brian Birdwell.

Photos of the explosion -- which reportedly happened around 7:50 p.m. (8:50 p.m. ET) -- showed a huge blaze and flames leaping over the roof of a structure and a plume of smoke rising high into the air.

The West Fertilizer Plant is just north of Waco. A school and a nursing home are among the buildings near the plant, CNN affiliate KWTX reported

Texas Gov. Rick Perry said he is aware of the explosion, a spokesman said, and was working to get resources into the area.

Tommy Alford, who works in a convenience store about three miles from the plant, told CNN that several volunteer firefighters were at the store when they spotted smoke. Alford said the firefighters headed toward the scene and then between five and 10 minutes later, he heard a massive explosion.

"It was massive; it was intense," Alford said.

Chrystal Anthony, a nearby resident, said she saw the flames engulf a nursing home and an apartment complex.

"It was an apartment complex that was devastated, the nursing home. The fire was close to a residential area," Anthony said.

"It was like a bomb went off," said Barry Murry, a resident who lives about a mile away from the plant. "There were emergency vehicles everywhere. It has been overwhelming."

West, Texas, is a community of about 2,800 people, according to the U.S. Census Bureau.

Sitting about 75 miles south of Dallas and 120 miles north of Austin, West is one of 22 incorporated communities in McLennan County.

Some firefighters at the scene of a fertilizer plant explosion in Texas were concerned Wednesday night about anhydrous ammonia.

According to the Centers for Disease Control and Prevention, anhydrous ammonia is a pungent gas with suffocating fumes that is used as a fertilizer.

When exposed to humans, it can cause serious problems.