Nurse’s Disappearance Puzzles Sheriff, Family : Investigations: The Westlake Village woman was last seen Tuesday at a friend’s office. Relatives’ fears grow by the hour.

The last day she was seen, Kellie O’Sullivan told friends she had a million things to do: visit the bank, see her computer consultant, collect marathon photos from a running buddy, pick up her 5-year-old son from school.

The Westlake Village nurse did all her errands Tuesday except the last one, said Ventura County sheriff’s detectives, and she has not been seen since.

With each passing hour, O’Sullivan’s friends, family and police have grown more worried that something went terribly wrong.

“It’s just completely out of character--the world revolved around her son,” said Kevin White, her live-in boyfriend, who picked up the child that night. “If she couldn’t be there, there’s no way she wouldn’t have called me, her ex-husband . . . or her mother.”

By Thursday, O’Sullivan’s relatives and White had turned his home into a miniature command post, preparing flyers with her picture to be posted in the area and calling to learn if anyone is using her credit cards.

O’Sullivan had no reason to leave, they said.

The 34-year-old divorcee doted on her little boy, co-workers said, and never would have intentionally left him waiting two hours, nor simply left town without telling anyone.

She was preparing for medical studies at Moorpark College this fall and for a scuba-diving trip this weekend with White.

“We had all kinds of plans. . . . I just don’t believe this is happening,” White added. “This is really bizarre. Either she’s got amnesia or something else has happened.”

By helicopter and police cruiser, sheriff’s deputies continued searching rugged mountain roads Thursday between O’Sullivan’s home in the Westlake Village area of Thousand Oaks and the last place she was seen Tuesday, a friend’s office just a mile away.

But there have been no leads, Lt. Lary Reynolds said.

Tuesday began routinely enough for O’Sullivan.

Co-workers said she worked a normal morning shift at the West Hills Medical Group, where she had switched from full-time to part-time work in anticipation of starting her college studies.

She complained of being a little sore. She had finished 22 miles of the grueling 32.5-mile Bulldog Race, a marathon through the Santa Monica Mountains in 100-degree heat Saturday, but she seemed in good spirits, said co-worker Johanna Jager.

“She’s very bubbly, outgoing, energetic,” Jager said. “She just likes to exercise a lot, she does a lot of workouts, she works out in the gym with her boyfriend.”

About 12:30 p.m., co-workers said, O’Sullivan clocked out--papers in her arms and plans on her lips for trips to the bank, the dentist, the computer store, maybe the mall and a jogging partner’s office before picking up her son.

Lina Darakdjian, a fellow nurse, recalled, “She was saying she had ‘so many things to do this afternoon.’ ”

By about 1:15 p.m., O’Sullivan made it to Connecting Point, a Calabasas computer store. There, she and a salesman talked over a program he was writing to help her reorganize White’s bookkeeping for his horseshoeing business.

“I asked her how she was doing because she looked like she was hobbling a little bit,” said the salesman, Brad Matthews. “She said she was a little sore because she had run a marathon.”

Matthews said O’Sullivan seemed a little overwhelmed by the volume of information he handed her, but seemed neither depressed nor preoccupied. She left about 15 minutes later.

About 1:45 p.m., she showed up at the office of Dr. Stefan Feldman, a Westlake podiatrist who had become a running partner after treating her as a patient.

O’Sullivan, Feldman and another friend had run the marathon together, passing a camera back and forth to take snapshots of each other, and Feldman showed her the pictures, he said.

“We talked about the pictures, and she stated she was a bit tired from the run, her legs were sore and she was having a stomach problem,” Feldman said. “She seemed slightly quieter than normal, but she would have her moods.”

Feldman said O’Sullivan left a few minutes later, saying nothing about where she was headed, and he glimpsed the roof of her black 1991 Ford Explorer as it wheeled out of the lot--about a mile from her home.

“I just pray to God that she’s OK,” Feldman said.

At 6:30 p.m., her son’s school called home asking White to pick him up. “That really freaked me out,” White said.

Anyone with information on O’Sullivan or the car, license plate number 2VPL883, is asked to call the Ventura County Sheriff’s Department at (805) 494-8207.