New surveillance footage shows a Nashville police officer walking about a block from an RV just seconds before it exploded in downtown on Christmas, killing its occupant and injuring three others.
The footage was released Sunday hours after officials identified the person killed in the explosion as 63-year-old Anthony Quinn Warner.
In addition to injuring three people, the apparent suicide bombing severely damaged nearby buildings and affected cellphone networks.
Officials said they did not immediately know what Warner's motive was, which is why the incident has not yet been labeled domestic terrorism.
"When we assess an event for domestic terrorism ... it has to be tied to an ideology," said Doug Korneski, the special agent in charge of the FBI's Memphis office. "It's the use of force or violence in the furtherance of a political [or] social ideology — we haven't tied it to that yet."
Warner is believed to have acted alone, and there is no indication that there are other suspects.
One person, who previously employed Warner as a computer technician, told WSMV-TV that the FBI asked him whether Warner was paranoid about 5G, a technology that has become a focus of conspiracy theories, such as the QAnon mass delusion. He said Warner never mentioned it, and he was unaware of any particular ideology he may have had.
On Sunday, Nashville Mayor John Cooper told CBS's Face the Nation that the incident appeared to be an attack on infrastructure.
"To all of us locally, it feels like there has to be some connection with the AT&T facility and the site of the bombing," Cooper said. "You know, and that's a bit of just local insight in because it’s got to have something to do with the infrastructure."
In a press conference on Sunday, Nashville Police Chief John Drake praised the six officers who evacuated civilians from the area after the RV played a warning message that it would blow up in 15 minutes.
"They didn’t think about their own lives; they didn’t think about protecting themselves," Drake said. "They thought about the citizens of Nashville and protecting them."
In between broadcasting the warning message, the RV played music, one of the officers, James Luellen, told reporters.
“What I specifically … remembered was ‘Downtown, where the lights shine bright,’" Luellen said. "Later, the ATF agent I spoke to pulled it up, and it’s 'Downtown' by Petula Clark was a specific song that was played."
Another officer, James Wells, recalled the terrifying minutes before the bomb went off, saying he'd gone back to his car to get body armor, and then started walking back toward the RV.
"I literally hear God telling me to turn around and go check on [Officer] Topping... and then the music stopped and as I'm walking back toward Topping now, I just see orange, and then I hear a loud boom."
Wells said the blast was so intense he nearly lost his footing.
"[As] I started stumbling, I just tell myself to stay on your feet and stay alive," Wells said.
Topping also recalled the moment of the explosion, and how she ran to Wells and took cover with him in a doorway.
"I've never grabbed somebody so hard in my life," Topping said. "I will never forget the windows shattering after the blast all around me — it kind of looked like a big prop from a movie scene, all the glass breaking at once."
In a Fox News interview Monday, Tennessee Gov. Bill Lee thanked the responding officers for evacuating people from the scene.
"When they talk about putting their lives on the line, that's exactly what they did that morning," Lee said. "They ran into that situation and saved so many lives."
Lee also said he spoke to President Trump on Sunday to request emergency relief funding for the small business owners whose businesses were destroyed in the explosion.
"Small business owners have had a very difficult year to start with," Lee said. "When you see the damage down there... I see business owners with a new struggle."