As the criminal investigation continues into the origins of the deadly blast in West, the debate over policies that contributed to the tragedy has largely faded.

The ruins in West were less than a month old when Texas lawmakers began demanding answers. State Rep. Joe Pickett (D-El Paso) gaveled his Texas House Homeland Security & Public Safety Committee into session in May 2013, within weeks of the April 17 explosion. "The intent of this hearing is to try to shed light on where these facilities are located, what kind of chemicals that we're talking about."

They quickly found the 270 tons of explosive fertilizer grade ammonium nitrate (FGAN) stored in West were essentially unregulated, untracked and left in the hands of untrained first responders. The blast that killed 15 people also leveled houses, apartments, schools and a nursing home. All were located within a few hundred feet of the factory. As remains the case today, their proximity to hazardous chemicals was not governed by any state or federal law. Of the 40 similar facilities in Texas, 48 percent are within a half mile of a school, hospital or nursing home and 83 percent are within a quarter mile of homes.

"One out of three school children in America today attends a school within the vulnerability zone of a hazardous chemical facility," Sen. Barbara Boxer (D-California) told a joint hearing of the Senate Environment Committee and Senate Health Committee in December 2014. Following President Obama's Executive Order 13650, issued within days of the blast, federal agencies in 2014 released a report detailing ways to improve chemical safety.

David Michaels, Assistant Secretary of Labor for Occupational Safety & Health, testified before the joint committee, "OSHA is exploring other actions to improve the safety of chemical facilities, including changes to our emergency response standards, modernizing and updating the PSM standard and policies, regulating changes to improve ammonium nitrate safety, and developing targeted outreach and guidance products."

The same year, an opinion by then-Attorney General Greg Abbott (R-Texas) kept state records documenting where dangerous chemicals are stored secret, citing security concerns. Speaking to reporters in July 2014, Abbott suggested companies are still required to present that information on demand to members of the public. Asked how to find those companies, he offered, "You drive around the neighborhood."

As governor, Abbott signed a 2015 bill bill that gave tougher enforcement power to state regulators, tightened reporting requirements and ordered coordination with local first responders. State Rep. Kyle Kacal (R-College Station) authored House Bill 942, and told KVUE in May, "The industry now has a relationship with their local fire departments, the fire marshal, the state chemist. They're better in sync and cooperating, which is better."

"Following multiple investigations and Texas House hearings, it became clear that regulatory oversight of ammonium nitrate (AN) was largely patchwork and that local emergency personnel awareness of potential hazards were not consistent," Kacal wrote KVUE in a statement Wednesday in response to questions over the law's current implementation status.

"House Bill 942 sought to concentrate state regulatory oversight, allow for state and local fire officials to do regular inspections, and codify the new AN storage requirements," wrote Kacal. "According to agency personnel, all AN facilities are in compliance with the new storage requirements. I believe that HB 942, based on our information at the time, was a strong effort to eliminate the possibility of another AN disaster and a means to prompt local first responders to develop pre-fire planning assessments of AN facilities."

Other incidents have occurred since the West blast, yet recommendations finalized by the federal Chemical Safety Board in February 2016 to keep chemicals away from communities have gone unheeded. Attorneys for families pursuing civil claims related to the explosion sent KVUE a statement Wednesday reiterating their effort.

"The ATF did not investigate what exploded, why it exploded or who knew that it could explode. All of that is the subject of civil litigation to be heard by a McLennan County jury," wrote Steve Harrison and Zona Jones.