A massive explosion and fire this morning at a Houston, Texas manufacturing facility damaged homes and injured at least one person, according to news sources. The 4:15 a.m. blast at Watson Grinding and Manufacturing sent a fireball into the air and knocked nearby residents out of their beds. Houston Police Chief Art Acevedo tweeted that debris was scattered a half-mile from the explosion site. Acevedo said at least one person is unaccounted for.

Homeowners are reporting shattered windows, broken doors and – in one instance – a collapsed ceiling.

In the hour after the first blast, smaller explosions and flames continued to occur at the site.

Harris County Sheriff Ed Gonzalez tweeted that no evacuations were immediately ordered, although he said that first responders were going door to door near the facility to check on residents while firefighters fought the flames.

A local school district announced plans to keep students indoors all day due to concerns about air quality in the area.

There is no word yet on the possible cause of the incident.