What caused watson explosion?

According to law enforcement officials, the electric spark possibly ignited a gas leak that led to a significant explosion last week in Houston, killing two employees, injuring 20 others, and destroying hundreds of buildings.

Highly flammable propylene gas began to leak into the pipes connected to the reservoir inside the Watson Grinding and Manufacturing warehouse within about 24 hours of the pre-dawn explosion, said Fred Malinowski, the local special agent in charge of the U.S. Office of Alcohol, Tobacco, Guns, and Explosives.

Sensors may have detected a leak, Malinowski said, but it is not clear if the sensors were in position, working correctly, or warning the company of a problem.

Malinowski said there is no evidence to suggest arson, vandalism, or other criminal activity behind the January 24 blast.

Houston Fire Chief Samuel Pena said the ATF findings were preliminary, and it could take up to two months to decide the final cause.

Business workers Frank Flores and Gerardo Castorena were killed. Two other warehouse employees were wounded, along with 18 people from surrounding homes and businesses.

City officials say that 450 structures—mostly homes—were destroyed by a metal processing and manufacturing business explosion. Of those homes, 35 were severely affected.

City leaders claim they partner with non-profit agencies to see what help can be given to people whose homes have been destroyed but do not have the financial means to repair and rebuild.

John Watson, CEO of Watson Grinding and Manufacturing, said to KTRK-TV that he would repair all the damaged homes on Tuesday. He said his insurance company is going to do so.

However, later Tuesday, Watson released a statement recalling his earlier remarks, saying the person at fault and who pays for damages cannot be determined at this early stage.

Mayor Sylvester Turner said the city's legal department had contacted Watson to see what it would do to help those whose homes had been destroyed. The city also looked at whether any federal funding would be eligible.

Volunteers from various neighborhood organizations have also helped clean up and restore residents.

At least 13 cases have been brought against the organization since the blast, including the Flores family's wrongful death suit. Harris County and Texas filed one of the lawsuits claiming a breach of the Texas Clean Air Act by Watson.

Officials state the propylene—a colorless gas used to manufacture chemicals in plastics, synthetic rubber, and gasoline—burned after blasting. The gas was in the facility's 2,000-gallon tank. People exposed to propylene may become dizzy and light-headed, and the gas may also cause liver damage.

The county and state also say that the company could have neglected to maintain equipment and store chemicals in its factory.

Houston and Southeast Texas are home to the largest concentration of oil refineries in the United States. The area has suffered several explosions in recent years. Last July, a blast at the ExxonMobil refinery in Baytown, east of Houston, left more than a dozen people with minor injuries and put residents under shelter advice for three hours.

In December, two explosions smashed windows and doors from nearby homes in Port Neches' coastal town.