A dog and a cat perished Monday night in a two-alarm fire at a six-unit apartment building that displaced 15 to 20 residents at least for the night.

The cause of the fire at the Lodge Avenue apartments is under investigation and fire crews are looking for the cause, but the fire is not suspicious, Harrison Twp. Fire Battalion Chief Sean McNeil told News Center 7. He estimated the damage to the structure and contents at $50,000.

The two pets that died were in the unit where the fire started, he said, and the owner told fire crews she left and was gone for about 20 minutes when she got a phone call that her apartment was on fire.

Montgomery County sheriff’s deputies, who arrived ahead of the fire crews, attempted to get into the burning unit to free the animals, but smoke and flames drove the officers back, McNeil said.

No residents or firefighters were injured in the blaze that caused heavy fire damage to the one unit and heavy smoke damage to all of the units, McNeil said.

Fire crews dispatched to 3392 Lodge Ave. at about 8 p.m. on a report of a working fire found heavy fire and smoke, McNeil said, and that prompted dispatchers to upgrade the fire to two alarms — which sent crews from Butler Twp., Dayton, Huber Heights, Riverside and Vandalia to assist.

Russell Wimmer, who identified himself as one of the residents, said he heard what he thought was an explosion before he saw flames and smoke at the back of the building.

He said he called 911 and alerted his neighbors to get them out of the building.

“The fire just went down through there,” he said of the apartments, which are connected side by side on one floor. “I think I lost everything.”

McNeil confirmed what Wimmer and others said. He characterized the noise as a “loud pop” and said those statements would be factored into the investigation. The fire’s hot spot, he said, has been traced to the back bedroom of the unit where the pets died.

The Red Cross was called in to help the displaced residents find shelter for the night.