ATLANTA - Part of the roof of an industrial building on Atlanta Industrial Parkway collapsed early Friday morning after heavy rain moved through the area, authorities said.

What we know:

Atlanta Fire Rescue crews responded a little after 5:30 a.m. to 3755 Atlanta Industrial Parkway NW after a sprinkler system was triggered by the collapse. Fire officials said no injuries were reported, and the scene has been secured while an investigation is underway.

What they're saying:

Neighbors told firefighters and reporters that the building was previously used as a movie studio until about six weeks ago. Workers at a neighboring business said the structure was already in bad shape when they arrived.

"When we showed up, we thought it was fire damage because it was still dark," said Jacob Lusnia, who works next door for Pasco. "Everything was collapsed. It was only a cop here at the time. We watched the fire engine pull up and turn off the power. The sprinkler system was still going off."

Lusnia said a coworker was the one who called 911. He added that while someone mentioned there might have been people inside, he believed that was speculation.

The building appeared to sustain significant damage, with much of the roof caved in. Lusnia said he thought the collapse could have been caused by clogged roof drains that gave way under the weight of rainwater.

"It looks like the roof collapsed to me," he said. "That's probably a million dollars worth of damage."

What we don't know:

Atlanta Fire Rescue said the investigation continues.