One person is dead and two are in the hospital after being pulled from the San Joaquin River in Fresno County.
Rescuers rushed to the river off Highway 145 near Kerman just before 4 pm Sunday.
Officials say two people were swimming when they began to struggle.
That's when the trouble in the water quickly worsened, and the Fresno County Sheriff's Office says someone tried to come to their rescue.
"Bystader rushes in to help out," says Lt. Adam Maldonado. "As they're struggling inside the water, the bystander is able to help one of them out - pull them out. The bystander also starts struggling in the water."
The good Samaritan is expected to survive, and one swimmer was listed in critical condition Sunday night.
The second swimmer was still in the water at the beginning of the initial rescue and recovery.
Searchers later found that swimmer at the bottom of the river.
Officials are now urging caution in the water.
They say to wear a life vest and check for strong currents.
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