AUSTIN, Texas - Texas Gov. Rick Perry is calling the deadly fertilizer plant explosion in his state "a truly nightmare scenario."
Authorities have said as many as 15 people are feared dead and more than 160 others were injured in the explosion that leveled homes and businesses in the farming community of West, Texas.
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Perry emphasized during a Thursday morning news conference that much of the information about victims remains "very preliminary." He says President Barack Obama has offered a quick turnaround of declaring McLennan County an emergency disaster that is eligible for federal aid.
Perry says at least 75 homes were damaged in the blast. Lt. Gov. David Dewhurst says the explosion Wednesday night knocked people "all over the town" back 10 feet, including some through windows.
Waco Police Sgt. William Patrick Swanton says early Thursday he doesn't know how many people have been rescued since the Wednesday night explosion in downtown West.
But he says officials on the ground remain in "search and rescue mode," going building to building in the largely decimated neighborhood surrounding the plant.
He says he knows some firefighters still are missing, but one has been found and is in the hospital.
Swanton says a thunderstorm that rolled through the area early Thursday has helped in some ways, including tamping down chemicals released from the plant.
Swanton says there is no indication the blast was anything other than an industrial accident.
View West, Tx Fertilizer Plant Explosion in a larger map
According to ABC News, the blast was so strong, it registered a 2.1-magnitude earthquake.
Al Vanek, a West city council member, said a four-block area around the explosion "is totally decimated."
Some of damaged buildings are a housing complex with a collapsed roof, a nearby middle school and the West Rest Haven Nursing Home, where first-responders evacuated more than 130 patients.
Family members who are worried about loved ones can call 254-202-1100.
Texas National Guard at site of plant explosion
A spokeswoman says about 20 members of the Texas National Guard are on the scene of the fertilizer plant explosion working to help first responders.
National Guard Bureau spokeswoman Rose Richeson says the group's a civil support team. Its members act like consultants to first responders.
The unit typically has mobile labs and can perform air monitoring while also assessing chemical and biological hazards at disasters.
Richeson says other Guard forces that do search and rescue missions are on alert.
February planned burn at plant led to school evacuation
The school superintendent in the area of a Texas fertilizer plant explosion says in February, the plant carried out a controlled burn of unwanted brush, but didn't warn a school nearby.
School officials evacuated students from West Intermediate School as a precaution.
Last night's explosion at the plant leveled that same school.