(CNN)Four people were injured Sunday after an explosion at an Atlanta-area apartment complex destroyed several floors of a building, fire officials said.
The DeKalb County Fire Rescue Department completed its search and evacuation of the building and confirmed no one is trapped, the department said in a statement on Facebook on Sunday night.
The apartment complex is in the Perimeter area of Dunwoody, just north of Atlanta. The structure was stabilized after rescue teams shored up the parts of the building that were structurally unsound so they could be searched, the fire department said.
Calls about the explosion came in at 1:24 p.m., Dunwoody Police said on Twitter.
"The cause of this incident is under investigation," the DeKalb County Fire Rescue Department said.
Officials have not determined the cause of explosion, but the building's leasing agent reported a strong smell of gas about an hour before calls of the explosion came in, Deputy Fire Chief Melvin Carter of the DeKalb County Fire Rescue Department told reporters earlier.
A resident told CNN affiliate WGCL that before going to church Sunday morning, he smelled gas in the hallway and called the complex, telling them, "it's an issue. Obviously it's pretty heavy."
"I jokingly said that if you light a match in here the whole building is going up," the resident said in a video WGCL posted on Twitter.
On his way back home, the resident said his sister called him to let him know his "building just blew up." He had yet to know the extent of damage to his home or the fate of his two cats.
"There have always been gas leaks here and there around the entire complex," the resident added.
Antwone Williams, 32, who was working at a neighboring apartment complex at the time, said on Twitter he was "shaken up" after seeing an injured toddler screaming for help.
"I heard something like (an) explosion but felt an earthquake," Williams told CNN. "I was totally panicking and freaked out. I shut down our leasing office and quickly ran over to figure out what was happening."
"It could have been anyone. Pray for those affected," he added.
The sound and impact of the explosion was felt by others outside the complex.
Stacey Dougherty, a resident of The Bricks Perimeter Center Apartments about a quarter of a mile away, said she felt the explosion but thought it was her neighbor dropping something.
"I felt and heard a loud thud around 1:30 or so. I thought my neighbor dropped a large item like a piece of furniture," Dougherty told CNN. "I only found out a bit later on Twitter that it was a gas explosion just down the road from me. I hope no one got hurt."
The Red Cross was at the scene, which Carter had described as "very chaotic," to help residents displaced by the explosion.