WEST, Texas (AP) -- Rescue workers searched the smoldering ruins of a fertilizer plant Thursday for survivors of a monstrous explosion that leveled homes and businesses in every direction across the Texas prairie. As many as 15 people were feared dead and more than 160 others injured.

Daybreak revealed a breathtaking band of destruction extending outward from the West Fertilizer Co. in this small farming community about 20 miles north of Waco. The thunderous blast shook the ground with the strength of a small earthquake and could be heard dozens of miles away.

Several buildings with smashed roofs and leveled walls still were smoking early Thursday.

"They have not gotten to the point of no return where they don't think that there's anybody still alive," Waco Police Sgt. William Patrick Swanton said of rescuers.

The explosion that struck around 8 p.m. sent flames shooting into the night sky and rained burning embers and debris down on shocked and frightened residents. It leveled a four-block area around the plant that a member of the city council, Al Vanek, said was "totally decimated."

There is no indication the blast was anything other than an industrial accident, Swanton said.

The toll included 50 to 75 houses, an apartment complex with about 50 units that one state police officer said was reduced to "a skeleton," a middle school and the West Rest Haven Nursing Home, from which first-responders evacuated 133 patients, some in wheelchairs.

Swanton said earlier that authorities believe between five and 15 people were killed in the blast, but stressed it was an early estimate.

Three to five volunteer firefighters were among those believed to be dead, Swanton said. A single law enforcement officer who responded to a fire call at the West Fertilizer Co. shortly before the blast was accounted for early Thursday.

In the hours after the blast, residents wandered the dark, windy streets searching for shelter. Among them was Julie Zahirniako, who said she and her son, Anthony, had been playing at a school playground near the fertilizer plant when the explosion hit. She was walking the track, he was kicking a football.

The explosion threw her son four feet in the air, breaking his ribs. She said she saw people running from the nursing home and the roof of the school lifted into the sky.

"The fire was so high," Zahirniako said. "It was just as loud as it could be. The ground and everything was shaking."

William Burch and his wife, a retired Air Force nurse, entered the damaged nursing home before first responders arrived. They split up, searching separate wings, and found residents in wheelchairs trapped in their rooms. The halls were dark and the ceilings had collapsed. Water filled the hallways and electrical wires hung eerily from the ceilings.

"They had Sheetrock that was on top of them. You had to remove that," Burch said. It was "completely chaotic."

Some witnesses compared the scene to the 1995 Oklahoma City bombing, and authorities said the plant made materials similar to that used to fuel the bomb that tore apart that city's Murrah Federal Building.

Although authorities said it will be some time before they know how many lives were lost, they put the number of those injured at more than 160 early Thursday. West Mayor Tommy Muska told reporters that his city of about 2,800 people needs "your prayers."

"We've got a lot of people who are hurt, and there's a lot of people, I'm sure, who aren't gonna be here tomorrow," Muska said. "We're gonna search for everybody. We're gonna make sure everybody's accounted for. That's the most important thing right now."

At the Hillcrest Baptist Medical Hospital in Waco, elderly people were wheeled in on stretchers. A man in a wheelchair with his T-shirt covered in blood winced as medical professionals tended to wounds on his head and left arm.

The town's volunteer firefighters had responded to a call at the plant at 7:29 p.m., Swanton said. Due to the plant's chemical stockpile, "they realized the seriousness of what they had," he said.

Muska was among the firefighters, and he and his colleagues were working to evacuate the area around the plant when the blast followed about 20 minutes later.

The main fire was under control as of 11 p.m., authorities said, but residents were urged to remain indoors because of the threat of new explosions or leaks of ammonia from the plant's ruins. Swanton said early Thursday authorities were not concerned about lingering smoke from the fire, and noted that rain from a morning thunderstorm helped their efforts.

Dozens of emergency vehicles amassed at the scene in the hours after the blast. Firefighters used flashlights to search the still-burning skeleton of an apartment complex that was all but destroyed. All that remained of a nearby house was the fireplace and chimney, standing tall among smoldering embers of what was once someone's home. Smoke filled the air.

A flood-lit football field initially was used as a staging area, then other triage centers sprung up around the blast site. At one, an army of first responders evaluated senior citizens, many of whom were disoriented, dazed and panicked.

"Get them into an ambulance now," workers shouted.

Those who were OK were loaded onto school buses, many in wheelchairs, to be taken to evacuation centers.

About 100 of the injured were treated at Hillcrest Baptist Medical Center in Waco, where five people were in intensive care. Another 65 were taken to Providence Health Center in Waco. Officials said the injuries included broken bones, bruises, lacerations, respiratory distress, and some head injuries and minor burns.

Erick Perez, 21, of West, was playing basketball at a nearby school when the fire started. He and his friends thought nothing of it at first, but about a half-hour later, the smoke changed color. The blast threw him, his nephew and others to the ground and showered the area with hot embers, shrapnel and debris.

"The explosion was like nothing I've ever seen before," Perez said. "This town is hurt really bad."

President Barack Obama released this statement on the explosion:

"Today our prayers go out to the people of West, Texas in the aftermath of last night’s deadly explosion at a fertilizer plant. A tight-knit community has been shaken, and good, hard-working people have lost their lives. I want to thank the first responders who worked tirelessly through the night to contain the situation and treat the wounded. My Administration, through FEMA and other agencies, is in close contact with our state and local partners on the ground to make sure there are no unmet needs as search and rescue and response operations continue. West is a town that many Texans hold near and dear to their hearts, and as residents continue to respond to this tragedy, they will have the support of the American people."

The U.S. Chemical Safety Board said it was deploying a large investigation team to West. An Alcohol, Tobacco and Firearms national response team that investigates all large fires and explosions also was coming in, bringing fire investigators, certified explosives specialists, chemists, canines and forensic specialists. But entry to the blast site wasn't expected until later. "It's still too hot to get in there," saidFranceska Perot, an ATF spokesperson.

There were no immediate details available from police on the number of people who work at the plant, which was cited by the Texas Commission on Environmental Quality in 2006 for failing to obtain or to qualify for a permit. The agency acted after receiving a complaint in June of that year of a strong ammonia smell.

In 2001, an explosion at a chemical and fertilizer plant killed 31 people and injured more than 2,000 in Toulouse, France. The blast occurred in a hangar containing 300 tons of ammonium nitrate, which can be used for both fertilizer and explosives. The explosion came 10 days after the Sept. 11, 2001, terrorist attacks in the U.S., and raised fears at the time it was linked. A 2006 report blamed the blast on negligence.

More Home Video of the Explosion (Warning: Graphic + Disturbing)

Residents Talk About the Explosion + the Aftermath in West, Texas

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