Photo: Lance Iversen, The Chronicle

ISLETON, Calif. (KCRA) — The search continues for a father who jumped into the San Joaquin River near Isleton after his 1-year-old son fell off a boat and into the river Friday, officials said.

The 1-year-old boy was later found and is in serious condition. The man is still missing, officials said.

Crews suspended the search for the 41-year-old father Friday night and will return Saturday morning. A crew from the Coast Guard is staying out on the river overnight. They want to be ready the second they're needed.

The 1-year-old boy was wearing a life jacket when he fell off the boat at around 11:30 a.m., and his father, who did not have a life jacket, jumped in after him, according to the Sacramento County Sheriff's Office.

Officials said that the man was on the boat with his three children when one of them fell into the river. The 10-year-old girl, along with a younger sibling, called authorities after their father jumped in after the 1-year-old child.

"We heard sirens going by," said Judy Vandeventer, who lives nearby. "They were going back and forth."

As crews rushed to the river, the girl helped them find her.

"She was able to see him driving down the road," said Sgt. Shaun Hampton, with the Sacramento County Sheriff's Department. "She said, 'Hey, you're passing me now. Back up.'"

When authorities arrived at the scene, officials took in the two older children while crews searched for their father and the 1-year-old.

After crews rescued the two children on the boat, they were able to locate the 1-year-old floating in river, the Sheriff's Office said.

"That's when we saw the Coast Guard bringing in the three children," Vandeventer said. "They were doing CPR on the baby on the dock."

Officials said the 1-year-old did not initially have a pulse, so first responders performed several life-saving measures, including CPR.

"The helicopter landed on the road and they evacuated the little one," Vandeventer said. "Then the two others got into the ambulance with the police officers."

By the time the 1-year-old got to the hospital, he had a pulse, the Sheriff's Department said. The toddler was initially listed in critical condition; his condition was later upgraded to serious.

Crews continued to search for the father until nightfall before suspending the search.