Jo Jo Passes Out on Stage

On Saturday K-Ci and Jo Jo performed at Enmore theater in Sydney, Australia. Jo Jo passed out on stage mid song. A fan said:

"So last night some friends and I went to see a Jodeci reunion tour at the Enmore theater in Sydney. Mate, the whole thing was a disaster. First, one of the guys (Devante I think) didn’t even show up, so it became a K-ci and JoJo concert. JoJo came on stage and right away you could tell he was messed right up- he kept forgetting the words to songs and just was a general weirdo. But then, after about 40 minutes into the "show" he decided to sit right down on the floor. His brother, the other crackhead K-ci was trying his best to carry the show on his own. By far, the best part of the evening was when JoJo walked off stage for about 5 minutes, then came back out to sing "All My Life"- and PASSED OUT mid song. His brother told the audience that they were tired after their 24-hour flight and that JoJo had gotten dizzy."

Why did everyone just leave Jo Jo lying face down on the stage?