Fire officials said it could take weeks to determine the cause of a massive fire that leveled an apartment building under construction in Berks County early Tuesday morning.

The flames erupted around 3:30 a.m. at the Legacy at the Papermill apartment complex, an over-55 community in the area of Calming Drive and Legacy Boulevard in Lower Heidelberg Township, according to emergency officials.

The 3-story building, consisting of just plywood and studs, burned to the ground, said fire officials.

"I had never seen anything like that before… it was an inferno," said Ray Bickley, whose nearby home was damaged by heat alone. "The glass pane of the window was popping because of the heat."

His home's vinyl siding also melted.

More intense damage was faced by the apartment complex beside the blaze. There, officials said three families needed to be temporarily evacuated.

"They just stayed in some ambulances to stay warm until they were able to get back into their apartment," said Chief Thomas Deiterich, Lower Heidelberg Twp. Police Dept.

Fortunately, Deiterich said no one was injured, including firefighters among the 12 departments that were called to the scene.

Aerial of Lower Heidelberg fire

The view from above shows the extent of destruction caused by the fire.

As of Tuesday afternoon, a cause and origin were unknown. Officials said the fire was under active investigation by a state police fire marshal.

Deiterich told 69 News that the apartment building was nearly completed structurally before the fire, but still needed drywall and insulation.

He said the building is now a total loss, with damage estimated around $2 million.

The owner of the property, Marc C. Powell, spoke with 69 News reporter, Dwayne Parker, by phone Tuesday evening.

 Powell said the entire day was a whirlwind for him.

 He also said he plans to re-build.