Missing: Joshua Williams - KMSP-TV

It's a tragic way to end the Labor Day weekend as the search continues for a missing man who was last seen on Saturday afternoon.

Maricopa County Sheriff's deputies are searching the Salt River, looking for 22-year-old Joshua Williams, who disappeared while tubing with some friends. Williams was between Sheep Bridge and Mud Cliffs before he became separated from them.

Deputies say they aren't sure if Williams became angry and simply walked away from his friends or if he drowned in the river.  

For some unknown reason, Williams untethered himself from the group and hasn't been seen since.

"They came around the bend and he did not come around with them," said MCSO's Chris Hegstrom. "They thought maybe he got out, maybe he did some other things..they finally went home..they went back to Chandler where they're from.  Realized he hadn't made it there and then they called us, so at about 9:00 last night we began searching for him."

"It's definitely a reality check, when we're all laughing around, goofing off and then we see that it's kind of..wow," said Bryce Dreifus, a swimmer.

Deputies say Williams knew how to swim and they don't believe alcohol was involved at all.

The dive team finished their search for the day and tell FOX 10 other crews will start to wrap up once the sun sets.

Williams is described as a black Male, 6' 3" tall, 200 pounds with black hair and brown eyes.  He was last seen wearing a white T-shirt, black jean shorts and black tennis shoes.

If you have any information about this case, call the Maricopa County Sheriff's office.

TIPLINE: 602-876-1011