In a case reminiscent of the disappearance of Laci Peterson, a 27-year-old pregnant woman vanished during her daily morning jog, and distraught family and friends turned out Tuesday to search for her.

Lori Kay Hacking (search), who is five weeks pregnant, went out about 5:30 a.m. Monday, heading from her Salt Lake City home to nearby City Creek Canyon (search) and Memory Grove park for a run.

After she did not show up later for her job at Wells Fargo Bank, her husband, Mark Hacking, called police at 10:49 a.m., Detective Dwayne Baird said.

"She never made it in this morning and I panicked," a tearful and visibly shaken Mark Hacking told reporters. "I called the police. I raced over here and found her car."

Her silver Chevrolet sedan was still parked near the front gates of Memory Grove (search).

Lori and Mark Hacking had just learned Thursday that she was five weeks pregnant. They have been married five years.

Police said they've interviewed Mark extensively and there has been no indication of any marital problems.

"It's important that he be cleared of any suspicion from the beginning," his father, Doug Hacking, said.

What makes the case all the more mysterious is that the area where Lori disappeared is not isolated or remote. The canyon that is the focus of the search is only about 200 yards from the state Capitol building.

Lori Hacking was last seen by a witness Monday morning when she was stretching near the park, Baird said. She is 5 feet, 3 inches tall, weighs 115 pounds and has hazel eyes, a dark complexion and long, dark brown, wavy hair. A Web site has been set up with more information.

Family, friends, co-workers and authorities joined in searching the area Monday, aided by search dogs and helicopters. Some of the searchers were on horseback. The search resumed Tuesday morning, with more than 1,200 people joining in by early afternoon, and police were hoping that as many as 3,000 volunteers will help look for the woman.

"We love you so much and we're doing everything we can to bring you home," Lori Hacking's mother, Thelma Soares, said, weeping as she held up her daughter's photograph.

Soares said several people from her church and work, along with hundreds of strangers, have shown up to look for her daughter.

Among those helping were relatives of Elizabeth Smart (search ), who was allegedly kidnapped in 2002 by transients and found nine months later with them in a Salt Lake suburb.

Elizabeth's mother, Lois Smart, told FOX News the disappearance of Lori Hacking really hits home.

Mark Hacking, a soon-to-be medical student, said he was grateful to the people who have volunteered to search for his wife.

"It really blows me out of the water to see how many people care and are willing to give so much of themselves," he said.

Volunteers were separated into groups of six and sent out to search the area surrounding an eight-mile paved trail that runs up the canyon, Baird said. The canyon was searched twice Tuesday, but there were no signs of Lori Hacking.

The search started about noon Monday with police using dogs and helicopters. SWAT team members were perched high atop a ridge overlooking the canyon, peering downward overnight with infrared binoculars.

Besides being a popular place for runners and cyclers, City Creek Canyon is also home to transients who camp in the brush. Several transients were interviewed Monday as they left the canyon, which has been closed, Baird said.

The woman's brother-in-law, Scott Hacking, said she has gone running about three times a week for four years.

"She's very familiar with the area. She's in very good shape," he said.

Mark Hacking works the night shift at an inpatient psychiatry unit and usually is sleeping when Lori Hacking goes running. She normally returns home about 6:30 a.m. to shower and get ready for work. "Then I usually drive her to work," he said.

On Monday, he woke up later in the morning to find Lori hadn't awakened him for her ride to the office. Mark Hacking called Wells Fargo and learned his wife had not showed up for work.

The park and canyon have been closed to everyone but searchers, Baird said.

The couple planned to move next week to Chapel Hill, N.C., where Mark Hacking is to attend medical school.

Mark's sister, Tiffany Carpenter, said the family felt "helpless not knowing where she is.

"We're just all trying to spread out and be the most help," she said. Some family was comforting Mark while others searched or helped in other ways. Other family members were flying in from Texas and Washington.

The search was scheduled to continue until dusk Tuesday evening, and Baird would not speculate whether it would resume Wednesday.

Many volunteers, including missionaries for The Church of Jesus Christ of Latter-day Saints wearing slacks, white dress shirts with their LDS name tags, returned with grass-stained shirts and mud up to their knees. A thunderstorm had doused the area overnight.

Orrin Olsen, 51, of Provo, works with Soares at the LDS Foundation, the fund-raising arm of the Mormon Church, and made plans to join in the search after an e-mail circulated in their office Monday afternoon.

"We really think a lot of Thelma and her family," Olsen said. "We got here first thing."

Anyone who has information about Hacking is asked to call the Salt Lake City Police Department at 801-799-3000 or 801-799-4636.

Fox News' Alicia Acuna, Catherine Donaldson-Evans and The Associated Press contributed to this report.