BLOOMINGTON, Ind. — Dozens of volunteers headed back out Tuesday to look for a 20-year-old Indiana University student who was last seen on her way to her apartment near the Bloomington campus five days ago.

Rebecca Spierer thanked all those who gathered outside the apartment of her missing sister, Lauren, before they resumed their search of the neighborhood and the wooded countryside around the small southern Indiana city.

Police say Spierer was last seen walking alone about 4:30 a.m. Friday a few blocks from her apartment following a night of partying with friends.

Rebecca Spierer travelled with her parents, Robert and Charlene Spierer, from their home in Greenburgh, N.Y., to help look for the missing student. Charlene Spierer said she was praying for a lead.

"She didn't just disappear. Somebody knows where she is," she told NBC's "Today" show. "If you had a thread of decency ... I'm begging. Somebody knows where she is I just want them to help us."

The hunt for Spierer is reminiscent of the search for IU student Jill Behrman who was 19 when she went missing during a bike ride near Bloomington in 2000. Hunters found her skeletal remains three years later in a remote field about 15 miles from the city.

Eric Behrman, Jill's father, said he would encourage Spierer's family to remain positive and hopeful.

"It brings back the memories," Behrman said, as he joined the volunteer search crews Tuesday. "We couldn't help thinking what initially we went through."

Fliers featuring Spierer's photo and describing her as 5 feet tall and 90 pounds have been distributed across Bloomington. She had just finished her sophomore year at IU studying apparel merchandising, and friends say she was taking a summer class before returning home for an internship in New York City.

Her parents have said she needs medication for a condition that causes irregular heartbeats.

Information from: The Herald Times,