ORLANDO, Fla. — There were thousands of people in the terminal at Orlando International Airport Friday when a loud explosion was heard followed by the discovery of a smoldering bag.
What was initially thought to be a gunshot or explosive device ultimately was determined to be a lithium battery that overheated and exploded, officials said.
Regardless, chaos ensued, witnesses said, and Greater Orlando Aviation Authority CEO Phil Brown said that is something that will have to be addressed.
"What went right about it: We were able to determine that it wasn't a threat and get people back into the terminal and we were able to recover pretty quickly given the circumstances," he said. "What didn't go over well for us is there was a lot of miscommunication and I'm not sure how you address that when you have thousands of people in a terminal."
Carolyn Barber was in the security line with her father when the explosion was heard and the smoke started pouring out of the bag.
"This backpack was on the ground and it started just smoking, white smoke coming out of it, and people were screaming," she said.
A Transportation Safety Administration agent was the first person to approach the bag and quickly moved it away from bystanders.
The TSA agent, Army veteran Rick Perez, 20, said he believed the bag to be an improvised explosive device. He placed it between a concrete column and a concrete planter to mitigate any harm that might come with a full explosion.
"Somebody yelled, 'Bomb,' or 'Bag,' and that set everything off," Perez said. "I radioed in that we had a bag that was potentially an IED and smoking, and I picked it up and put it some place that I thought less casualties might occur."
Watch: Army veteran TSA agent moves bag away from passengers
The TSA commended Perez, saying he ran the bag away even as panicked passengers "knocked over the queuing stanchions and dropped roller bags, creating loud banging sounds which were perceived as gunshots, further spreading panic throughout the airport."
Read: Traffic heavy at OIA after lithium-ion battery explosion cancels 24 flights
Numerous people at OIA reported there was a panic caused by those loud noises, initially thought to be gunshots.
"Our TSA Team's performance was outstanding. I'm very proud of our team and how they responded to both the incident and the recovery process of rescreening passengers," said Jerry Henderson, TSA Federal Security Director. "Our people responded as they are trained to do, and to lead passengers to safety."
While the noise and smoke were quickly connected to the lithium battery and announcements were made over the airport's public address system, no one heard them in the tumult.
"It's clear that there was a lot of confusion and human nature took its course," Brown said. "There were a lot of people that were running for, what they thought, were their lives."
Read: Gunman in military gear caused scare at OIA, police say
The confusion caused officials to initiate a ground stop on all flights, which caused massive delays and lines as people evacuated had to going through security screening for a second time.
"As a result of the incident, a ground stop was issued and a number of flights were held while passengers were allowed back into the building and security checkpoints reactivated," airport officials said in a statement.
Photos given to Channel 9 at the time of the incident showed a normally busy terminal that was completely empty.
[ Watch: Examining the dangers of lithium batteries ]
A video showed people evacuating trams at the airport.
Hours after the battery explosion, massive crowds continued to work their way through security to get to their flights.
Perez, speaking to Channel 9 via Skype, said he wasn't scared when he picked up the smoldering bag, but he was hit by the realization of how dangerous it was after the incident was over.
Many other TSA agents performed heroically Friday and potentially put their lives in danger as well, Perez said.
"I was the one that got caught on camera, basically, but there were a lot of TSOs that were out there working, getting folks away from that area," he said. Carrying children, people who needed help. Elderly people in wheelchairs.
"I wasn't the only one."
Airport officials announced Monday that they would be looking into a system that would amplify the PA system so passengers are able to hear instructions during any future incidents.