Michael Barnett captured dramatic video of the fire, on Interstate 30 just northeast of Dallas, and uploaded it to CNN iReport
. Smoke and flames poured from the rear of the bus as traffic slowed to a crawl and Barnett slowly approached in his vehicle.
As he drew closer to the bus, Barnett decided to stop filming because he didn't know what to expect.
"It was shocking," he said. "I didn't know what I was about to see. I didn't know if anyone was hurt."
Barnett said he didn't realize at the time that the bus belonged to the country band.
Hillary Scott, co-lead singer for the band, posted a photo of the charred bus on Instagram and noted that she, her husband, the tour manager and the driver were all evacuated safely.
"Thanking God for our safety and the safety of all of those who helped put this fire out and keep us safe," she wrote.
The tour manager told CNN affiliate KTVT
that the bus stopped after a rear tire blew out. It burst into flames after everyone had gotten off.
Scott also posted an Instagram photo and message saying that the fire destroyed everything in the bus's back lounge except her Bible.
The band's two other members, Charles Kelley and Dave Haywood, were not traveling on the bus, KTVT reported.
Lady Antebellum is set to perform at the 50th Academy of Country Music Awards on Sunday in Arlington, Texas.