According to local police, another customer attempted to use machine but said it was not functioning. Shortly after receiving a refund and choosing another machine, the first one turned on, with the five-year-old in its basin.
"She was tumbling pretty fast in there," Vance Mitchell of the Pasadena Police told KHOU.
"One person walked by and said they saw something flopping around in there. They thought it was just a dress or something because it was moving pretty fast."
The young girl was airlifted to nearby Memorial Hermann Hospital in Houston.
It remains unclear how the girl was able to get into the machine or what caused its delayed start. The only thing police can say for sure is whomever was responsible for the child acted negligently.
"You've got to watch your kids. That's the bottom line. If that was my son or granddaughter, I'd be really upset that I let it happen."
The girl is expected to fully recover from her injuries.