Jan. 24 (UPI) -- A powerful explosion at a plastics manufacturing warehouse in Houston killed two people Friday, Houston police Chief Art Acevedo said.
The blast could be felt for miles around the Texas metropolitan area around 4:30 a.m.
Acevedo said that though police don't believe a criminal or terror act is to blame for the explosion, officials launched a criminal investigation.
Houston Fire Chief Samuel Pena said investigators aren't sure yet what caused the explosion, although the warehouse owner said it originated from a tank of flammable propylene gas.
Initial readings indicated no hazardous chemicals were released into the air, so no evacuations were needed, officials said. Residents were warned to stay away and a hazardous materials team was sent to the site.
The Houston Fire Department said 48 people in the area were sheltered in a nearby church. The Red Cross was working to establish an overnight shelter.
Two nearby schools were closed for the day and students at other schools were told to stay indoors.
Officials said 18 people self-reported to local hospitals complaining of "minor injuries" associated with the blast, including breathing problems and cuts.
Aerial news footage showed damaged buildings at the Watson Grinding and Manufacturing, a machining and manufacturing company.