VIDEO: Massive damage but no deaths in propane plant blast

And for a time, it seemed their fears were well-founded.

The loud blasts, one after another, at the Blue Rhino plant in Tavares sent huge plumes of fire into the night sky. "Like bombs are going off," Tavares resident Norma Haygood told CNN affiliate WESH.

Eight plant workers went to hospitals. And authorities couldn't find 15 others.

There were 53,000 20-pound cylinders of propane at the facility -- more than a million pounds in all, said John Herrell, a spokesman for the Lake County Sheriff's Office.

Firefighters immediately set up a half-mile evacuation area around the plant. The nearest homes -- about 50 of them -- are about three-quarters of a mile away, Herrell said.

And they began pouring water onto the facility.

Trucks parked at the plant went up in fireballs as the cylinders they were carrying exploded. The nighttime sky flickered in hues of orange.

"You could see the explosions from across the lake," said Ashley McCormick, a resident in nearby Mount Dora. "They were very intense."

By 2 a.m., about three hours after the explosions began, fire crews finally gained a handle on the situation.

Fortunately, all 15 of the missing workers were found safe. Some had fled the scene; some drove themselves to hospitals.

No residents were hurt.

"The fact that there are no fatalities is a blessing," said John Drury, the city administrator of Tavares, a community of some 14,000 people about 30 miles northwest of Orlando. "This was a big deal, and a lot of people responded quickly."

Now, the focus shifts to what caused the blasts.

The Blue Rhino facility refills propane tanks used in gas grills. The company's tank exchange service allows customers to trade in an empty tank for a full one at retail locations.

The Occupational Safety and Health Administration fined Blue Rhino in 2011 over a "serious" safety violation involving tools and equipment. It is not clear whether safety violations had anything to do with the fire.