Video from the concert shows Neil give a spin with his guitar by his side and then walk to the side of the stage before slipping out of sight.
The band finished the song and then carried on, playing a Led Zeppelin cover, according to fan Darrell Jenkins, who shot this video.
In another video, bass player Dana Strum explained to the crowd that Neil was hurt.
“The truth is Vince fell and broke ribs when he fell,” Strum said. “He can’t breathe and he’s gonna get dealt with medically.”
Strum said Neil wanted to tough it out and finish the show, but was told he shouldn’t.
Neil has not posted any updates on his condition on social media.
The band then launched into Mötley Crüe’s “Live Wire” and urged the audience to sing along, so Neil could hear them backstage.
Jenkins tweeted that Neil looked good and was singing great before the fall.