The riverboat may have a tank holding hundreds of gallons of fuel.
The 87-foot Spirit of Sacramento is upside down and now sits in a stretch of water known as False River in the Delta by Bethel Island.
Up close look at "Spirit of Sacramento" paddle boat that flipped over in the Delta. pic.twitter.com/a10pxvzEeZ— Laura Anthony (@LauraAnthony7) September 5, 2016
It had mechanical problems and started taking on water before sinking early Sunday morning.
The riverboat was anchored a few days before it sank. It appeared in the area in the past two weeks, but it's still a mystery to the people who work and live there as to what happened. "On Sunday morning, my neighbor who went by the boat, he said the boat was listing to one side," Bruce Johnson said.
Johnson told ABC7 News he saw the riverboat start to take on water on Sunday morning. "Went back in the house, got my friend, said 'hey, this boat looks like it's going down,' walked back out and there was no more boat there. It had rolled and sunk," he said.
The U.S. Coast Guard told ABC7 News the riverboat began to capsize earlier Sunday and the two men who had been aboard were gone. "At this point we haven't heard anything from the owners, we've attempted to contact them," U.S. Coast Guard spokesperson Nicole Emmons said.
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The people on the riverboat told locals they recently purchased it at auction for a $1,000.
A few days ago, the Contra Costa Sheriffs Marine Patrol boarded the Spirit of Sacramento, cited the owners, and told them they would have to move along. They tried, but didn't get very far.
"It's a mess," Janet White said.
White went out to see the debris up close. "There's diesel fuel all over, there's barstools, there's chairs, and propane tanks, ice chests just floating," she said.
The U.S. Coast Guard says the riverboat may have had as much as 600 gallons of diesel on board.
A salvage company is working to the remove the wreckage, an operation that could cost taxpayers as much as $100,000.