In 2013, fifteen people were killed and more than 260 injured after a fertilizer plant in West, Texas, exploded. Investigators still have not determined the cause of the fire that triggered the explosion, but a federal report released last week found that 19 plants in Texas alone are located in similarly dangerous proximity—less than half a mile—to schools, nursing homes, and housing.

The report was issued by the United States Chemical Safety Board. “Many communities in Texas and nationwide are located too close to facilities resembling” the West, Texas, plant, investigators concluded. The “risk to the public from a catastrophic incident exists at least within the state of Texas, if not more broadly.”

The agricultural chemical that set off the deadly explosion (fertilizer-grade ammonium nitrate) is not officially designated an explosive or hazardous material. From the New York Times:

The force of the blast registered as a 2.1-magnitude earthquake. Officials in the past have cited 14 confirmed deaths; 10 of the victims were volunteer firefighters and emergency responders. The report cited 15 deaths, adding a victim who lived at a nursing home damaged by the blast and died shortly afterward. Of the town’s 700 homes, about 350 were affected by the explosion, including 193 that were destroyed or severely damaged. Three of the town’s four public schools were destroyed or had major damage.

The Chemical Safety Board called it one of the most destructive episodes the agency had investigated. The fertilizer was stored at the plant in a wooden warehouse in wooden bins, in a building without a sprinkler system, in a state that has no statewide fire code.

According to the Houston Chronicle, fertilizer-grade ammonium nitrate is a staple crop treatment—particularly in rural areas like West, where fire departments are often made up of volunteers. The firefighters in West were unaware of fertilizer-grade ammonium nitrate’s explosive potential, the report found, and moreover had not been properly trained in how to respond to something like a fertilizer plant burning.

More than 1,300 plants across the country store fertilizer-grade ammonium nitrate. On Thursday, agency Chairwoman Vanessa Allen Sutherland said, “It’s possible for another type of incident like this to happen.”

Photo via AP Images. Contact the author of this post: brendan.oconnor@gawker.com.