Seven workers were injured last night – three of them critically – when dozens of explosions and a fire ripped through a propane tank servicing plant in central Florida. Residents living within a mile of the facility were ordered to evacuate their homes.

News sources reported that approximately two dozen workers were on duty at the 33,000-acre Blue Rhino facility in Tavares, 40 miles northwest of Orlando, at the time of the blasts, which began around 10:30 p.m. EST.

The plant housed about 53,000 20-pound propane cylinders. At times, observers said one tank was exploding every few seconds. The blasts were felt up to six miles away and flames were visible shooting up into the night sky.

The company cleaned and refilled propane tanks used for home gas grills – as many as 4,000 to 5,00 tanks each night.

According to a spokeswoman for the Orlando Regional Medical Center, the three critically injured men being treated at the center are suffering from burns.

The cause of the explosions is not yet known. The Tavares fire marshal is conducting an investigation.

Blue Rhino is a subsidiary of Ferrellgas Partners, the second-largest distributor of propane in the U.S.