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Three sisters — on a trip to celebrate their dad’s birthday — were on the doomed diving boat that caught fire and sunk off the coast of Southern California early Monday, their mother says.

They are believed to be among the 34 people presumed dead.

“It is with a broken heart … 3 of our daughters were on this boat,” wrote Susana Rosas, of Stockton, in a Facebook status Tuesday. “My #1, Evanmichel Solano Quitasol, my #3, NicoleStorm Quitasol and my #4, Angela Rose Quitasol.”

The sisters, who are all adults, were on the 75-foot boat — dubbed the Conception — with their father, Michel Storm Quitasol, and their stepmother, Fernisa Sison.

“We are getting the latest information from the media,” Rosas said. “The authorities do not have much to say to us. Thank you to all of you for your support prayers and good wishes.”

Evan Quitasol has been described by friends and family as a nurse at at St. Joseph’s Medical Center in Stockton, where Michel and Sison had worked after reportedly attending nursing school.

Rosas’ husband, Chris, told the Los Angeles Times that Nicole Quitasol worked as a bartender in Coronado — near San Diego. Angela Rose taught science at a Stockton middle school.

A GoFundMe page has been created to help Michel and Fernisa’s families deal with the sudden loss.

Authorities are still trying to piece together why and how the Conception caught fire early Monday morning while on a dive excursion near Santa Cruz Island.

Almost everyone on board was asleep — below deck — when the blaze broke out, officials said.

Two students from an elite California high school, a female ship cook and the owner of the diving company that chartered the ill- fated boat trip are also believed to be among those feared dead.

The two students attended the Pacific Collegiate School in Santa Cruz, and both they and a pair of parents from the community were aboard the doomed boat Conception, local KSBW-TV reported Tuesday.

“Our hearts and prayers are with the victims and for the families of those missing, particularly those of our students,’’ the public charter school, which consists of grades seven through 12, said in a statement.

Also aboard the ship was Kristy Finstad, a 41-year-old marine biologist who along with her husband ran Worldwide Diving Adventures, which had hired the boat for the three-day holiday-weekend diving excursion off the coast of Santa Barbara.

Finstad’s husband was in Costa Rica and not part of the trip.

“No final word on my sister Kristy; however, it is likely she has transitioned to be with the good Lord,” Finstad’s brother, Brett Harmeling, wrote on Facebook.

Kristy inherited the diving business from her father when he retired. Her brother told the Los Angeles Times that his sister was tenacious, and, “If there was a one percent chance of her making it, she would have made it.’’

Thirty-three passengers and one crew member were still aboard the ship when it sank early Monday, according to officials.

The sole crew member feared dead was a 26-year-old female cook, her sister told KTLA-TV.

The sibling was at a makeshift memorial for victims and lamented that she hadn’t heard from her sister since the tragedy.

“She was an amazing person,” said the sibling, who only gave her name as Olivia and declined to identify her sister. “She had the biggest heart. She was my role model, my big sister, she was everything to me, and she’s just gone now.”

Three passengers celebrated their birthdays aboard the ship hours before the fire, according to the Times.

They included a 17-year-old girl who was on board with her parents. It’s not clear whether the teen may have been one of the Pacific high school students.

Santa Barbara County Sheriff Bill Brown said Tuesday that officials have heard “anecdotally’’ that the victims included “some people in their sixties.’’

“The majority were from the Santa Cruz, San Jose, Bay Area region,” Brown said.

With Post wires