American Red Cross crews from across Texas were being sent to the site, the organization said. 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.
A West Fire Department dispatcher said any casualties would be transported to hospitals in Waco, which is about 90 miles north of Austin.
The explosion knocked out power to many area customers and could be heard and felt for miles around.
Brad Smith, who lives 45 miles north of West in Waxahachie, told the station that he and his wife heard what sounded like a thunderclap.
Lydia Zimmerman, told KWTX 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.
Rafael Abreu, a geophysicist with National Earthquake Information Center of the U.S. Geological Survey, said the explosion did not register on a seismograph because most of the blast's energy dissipated in the atmosphere.
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.