Updated April 18, 2013, 1:27 AM ET
WEST, Texas A massive explosion at a fertilizer plant near Waco on Wednesday injured dozens of people and killed an unknown number of others, leaving the factory a smoldering ruin and leveling buildings for blocks in every direction.
The explosion at West Fertilizer in West, a community about 20 miles north of Waco, happened shortly before 8 p.m. and could be heard as far away as Waxahachie, 45 miles to the north.
Although authorities said it will be some time before they know the full extent of the loss of life, Texas Department of Public Safety spokesman D.L. Wilson said just after midnight that an unknown number of people had died and more than 100 were injured.
West Mayor Tommy Muska told reporters that his city of about 2,800 residents needs "your prayers."
Watch live coverage of the explosion from KTVT Dallas on the left:
"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."
A member of the city council, Al Vanek, said there is a four-block area around the explosion "that is totally decimated." Wilson said the damage was comparable to the destruction caused by the 1995 bomb blast that destroyed the Murrah Federal Building in Oklahoma City.
Muska, who is also a volunteer firefighter, said the town's department went to the plant to fight a fire about 6:30 p.m., and the blast that followed knocked off his fire helmet and blew out the doors and windows of his home nearby.
He said main fire was under control as of 11 p.m., but residents were urged to remain indoors because of the threat of new explosions or leaks of ammonia from the plant's ruins.
Earlier, Department of Public Safety troopers were using their squad cars to transport those injured by the blast and fire at the plant in West, a community north of Waco, Gayle Scarbrough, a spokeswoman for the department's Waco office, told CBS affiliate KWTX Waco. She said six helicopters were also en route to help out.
Among the damaged buildings was what appeared to be a housing complex with a collapsed roof, a nearby middle school and the West Rest Haven Nursing Home, from which first-responders evacuated 133 patients, some in wheelchairs.
"We did get there and got that taken care of," Muska said.
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."
Information was hard to come by in the hours after the blast, and entry into the town of about 2,800 people was slow-going as the roads were jammed with emergency vehicles rushing in to help. Texas Gov. Rick Perry said state officials were waiting for details about the extent of the damage.
"We are monitoring developments and gathering information as details continue to emerge about this incident," Perry said in a statement. "We have also mobilized state resources to help local authorities. Our thoughts and prayers are with the people of West, and the first responders on the scene."
Dozens of emergency vehicles amassed at the scene and hours after the blast, fires were still smoldering in the ruins of the plant and in several surrounding buildings. Aerial footage showed injured people being treated on the flood-lit football field that had been turned into a staging area for emergency responders.
Al Vanek, a West City Council member, said first-responders were treating victims at about half a dozen sites, and he saw several injured residents from the nursing home being treated at the community center.
"Tomorrow is going to be a very sad day," Vanek said.
Glenn A. Robinson, the chief executive of Hillcrest Baptist Medical Center in Waco, said in an interview on CNN that his hospital had received 66 injured people for treatment, including 38 who were seriously hurt. He said the injuries included blast injuries, orthopedic injuries, large wounds and a lot of lacerations and cuts. The hospital has set up a hotline for families of the victims to get information, he said.
Robinson did not immediately return messages from The Associated Press.
Messages to Scott Clark, spokesman for Scott and White Hospital in Temple and Hillcrest Baptist Medical Center in Waco, were not returned Wednesday. A spokesman at Providence Health Center was not available for comment, a hospital operator said.
Debby Marak told the AP that when she finished teaching her religion class Wednesday night, she noticed a lot of smoke in the area across town near the plant. She said she drove over to see what was happening, and that when she got there, two boys came running toward her screaming that the authorities ordered everyone out because the plant was going to explode.
She said she had driven only about a block when the blast happened.
"It was like being in a tornado," Marak, 58, said by phone. "Stuff was flying everywhere. It blew out my windshield."
"It was like the whole earth shook."
She called her husband and asked him to come get her. When they got to their home about 2 miles south of town, her husband told her what he'd seen: a huge fireball that rose like "a mushroom cloud."
Lucy Nashed, a spokesman for Perry's office, said personnel from several agencies were en route to West or already there, including the Texas Commission for Environmental Quality, the state's emergency management department and an incident management team. Also responding is the state's top urban search and rescue team, the state health department and mobile medical units.
American Red Cross crews from across Texas were also heading to the scene. Red Cross spokeswoman Anita Foster said the group was working with emergency management officials in West to find a safe shelter for residents displaced from their homes. She said teams from Austin to Dallas and elsewhere are being sent to the community north of Waco.
The explosion knocked out power to many area customers and could be heard and felt for miles around. Lydia Zimmerman told KWTX-TV that she, her husband and daughter were in their garden in Bynum, 13 miles from West, when they heard multiple blasts.
"It sounded like three bombs going off very close to us," she said.
Tonya Harris of Groesbeck said she heard the explosion. "My husband and l were cleaning up the kitchen after supper," she said in an email, "and heard what we thought was someone running into our house. It shook our windows and doors. We immediately ran outside looking for the worst."
In 2001, an explosion at a chemical 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.