The 2013 fertilizer plant blast that killed 15 people and wounded another 226 in West, Texas, "should never have occurred," the chairman of the U.S. Chemical Safety Board said Tuesday.
Though the board's report says that at least 14 people were killed, the death toll was updated to 15 people in the days after the blast.
The board's investigation, released a few days after the first anniversary of the explosion, indicates that the incident was "preventable," Chairman Rafael Moure-Eraso said in a statement distributed to reporters that put blame on the company and government regulators.
"It resulted from the failure of a company to take the necessary steps to avert a preventable fire and explosion and from the inability of federal, state and local regulatory agencies to identify a serious hazard and correct it," Moure-Eraso said.
McLennan County, for example, didn't have an emergency response plan in place, and "the community clearly was not aware of the potential hazard at West Fertilizer," the report said.
A lack of fire codes was repeatedly cited in the report, with investigators noting that Texas didn't have a fire code and small counties are prohibited from having them. But, the chairman said, local fire departments need fire codes to "hold industrial operators accountable for safe storage and handling of chemicals."
The board's supervisory investigator, Johnnie Banks, said all levels of government also failed to adopt codes to keep populated areas away from hazardous facilities. This is not unique to West, Banks said.
"We found 1,351 facilities across the country that store ammonium nitrate," he said, adding that farm communities are just beginning to collect information on the proximity of homes and schools to ammonium nitrate storage facilities.
The investigation determined that "lessons learned" from responses to similar incidents were not disseminated to firefighters, 11 of whom died when the West plant exploded.
The probe said guidelines from the National Fire Protection Association and U.S. Department of Transportation recommend that firefighters evacuate the area surrounding "massive" ammonium nitrate fires and that the area be doused with water "from a distance." However, the report said, the guidance is vague because of the use of subjective words like "massive," "large" and "distance."
"All of these provisions should be reviewed and harmonized in light of the West disaster to ensure that firefighters are adequately protected and are not put into danger protecting property alone," Banks said.
U.S. guidelines for ammonium nitrate storage have been static for decades, the board said, but the United Kingdom in 1996 mandated that storage facilities be one story, well ventilated and constructed of concrete, brick or steel.
Moure-Eraso lauded the Fertilizer Institute for recently establishing guidelines for storage and transportation of ammonium nitrate, along with recommendations for first responders in the event of a fire. He further called on all states and counties to likewise update their guidelines.
"The state of Texas, McLennan County, (the Occupational Safety and Health Administration) and the (U.S. Environmental Protection Agency) have work to do because this hazard exists in hundreds of locations across the U.S.," Moure-Eraso wrote. "However, it is important to note that there is no substitute for an efficient regulatory system that ensures that all companies are operating to the same high standards. We cannot depend on voluntary compliance."
Though the Chemical Safety Board investigates serious chemical accidents and makes safety recommendations, it does not issue fines or citations. The Bureau of Alcohol, Tobacco, Firearms and Explosives and the state Fire Marshal's Office said last week that their investigation into the cause of the fire remains active.
CNN's Ed Lavandera and Jason Morris contributed to this report.