Sam Rivers — the bassist for the nu metal group Limp Bizkit — died in a bathroom in his Florida home … and it sounds like he fell off the toilet.

TMZ obtained the incident report from Sam’s death … and in the documents, a deputy with the St. Johns County Sheriff’s Department says Sam’s wife, Keely, told law enforcement she found him face down in the bathroom before calling 911.

We obtained the 911 audio too, and you hear Keely telling dispatchers she found Sam in a pool of blood … then she gets emotional as she performs CPR.

The deputy says when they arrived, they performed CPR on Sam until St. Johns County Fire Rescue arrived and pronounced him dead. They say Sam appeared to have a cut over his eye, a possible result of a fall from the toilet.

In the report, the deputy says Sam’s face and neck were dark blue, while the rest of his body was flushed … which they note is commonly seen in instances of pulmonary embolism.

The deputy says they found a small amount of coagulated blood in the bathroom where he died, presumably from where he fell.

Sam’s wife told deputies her husband had a liver transplant in 2018 and was taking several medications for his liver and other related issues. She also told deputies Sam smoked weed and occasionally drank alcohol.

The official cause of death remains unclear.

Sam was an original member of Limp Bizkit and he temporarily left the band in 2015 after developing liver disease due to excessive drinking.

He was only 48.