A massive manhunt was under way Sunday as authorities searched for a gunman who killed five women who'd been herded to the back room of a clothing store during a botched robbery attempt.

At the Brookside Marketplace on Sunday, police tape flapped in the wind in front of the boarded-up Lane Bryant store where the shootings occurred while a dozen investigators scoured the area.

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Meanwhile, mourners erected a makeshift memorial of five white crosses and flowers outside the store as shoppers returned to the mall and tried to make sense Sunday of the brutal killings.

A tear rolled down Cindy Sorenson's cheek as she brought a bouquet of bright red roses to the Lane Bryant store Sunday morning.

Sorenson, who works as a store manager at a nearby mall in this community of nearly 60,000 people, said she didn't know any of the victims, but couldn't stop thinking about the women who died.

"Your job is your home," the 34-year-old Tinley Park resident said. "You spend so much time in a store and you never think anything like this will happen."

David Korbel knelt down on one knee and bowed his head in prayer by a curb in front of the store.

"I simply prayed for the families and for the authorities, so that they would get the man who did this," said Korbel, who lives in nearby Frankfort.

Officers found the victims at the back of the Lane Bryant store after getting a 911 call around 10:45 a.m.

Tinley Park Police Chief Mike O'Connell said a bystander told officers that he had seen a stocky black man, about 5-foot-9, who was wearing a black winter coat, a knit cap and dark pants.

The victims ranged in age from 22 to 37.

Lane Bryant's parent company, Bensalem, Pa.-based Charming Shoppes Inc., said in a statement Sunday that a store manager was killed along with four customers.

Chicago-area stores were closed Sunday in honor of those who died. The company said it was offering a $50,000 reward for information.

"The employees of Charming Shoppes and Lane Bryant are deeply saddened by the loss of life resulting from this horrific event," the company said in a statement. "We grieve for the innocent victims and our primary concern at this time is for the families and loved ones of those fatally injured."

A recording at the Will County Coroner's office said the women's identities would be released Sunday afternoon during a 2 p.m. news conference when police provide an update on the attack.

Four of the women were from suburban Chicago and one was from South Bend, Ind., authorities said.

"We do not want to compromise any evidence that may be out there ... I ask we keep family of the victims in our thoughts and prayers," O'Connell said.

Still, family members were beginning to identified the slain.

The sister-in-law of 33-year-old Carrie Hudek Chiuso said the Frankfort woman was one of the victims.

She declined to comment Sunday.

The other victims have been identified as Connie R. Woolfolk, 37, of Flossmoor, Ill., Sarah T. Szafranski, 22, of Oak Forest, Ill., Jennifer L. Bishop, 34, of South Bend, Ind., and Rhoda McFarland, 42, of Joliet, Ill.

Chiuso, a 1993 graduate of Homewood-Flossmoor High School, was a social worker at the school.

"Carrie was deeply loved by faculty and staff," said school spokesman Dave Thieman in a statement. "She had a real touch with students. The entire H-F family is deeply saddened."

Officers swept through neighboring shops at the strip mall in this southwestern Chicago suburb shortly after the shootings Saturday, but found no trace of the gunman.

Attempts to find him with dogs and a helicopter equipped with infrared sensors also failed, authorities said.

Tinley Park Mayor Edward Zabrocki said there were extra police patrolling nearby neighborhoods.

Meanwhile, the Chicago police department warned its officers to pay attention to strip malls and other Lane Bryant stores, police spokeswoman Monique Bond said.

Tinley Park police Sgt. T.J. Grady said investigators were trying to determine if there was video from security cameras mounted at nearby stores. O'Connell said the Lane Bryant store did not have a camera.

Police were allowing some shoppers into parts of the strip mall later Saturday, but had cordoned off the store.

Tracy Caccavella was shopping at a Pet Smart store late Saturday morning across the parking lot from the The small red and brown brick Lane Bryant is part of a cluster of four or five stores isolated on one side of a large blacktop parking lot, with big box stores including Target and a Best Buy several hundred yards away.

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The Associated Press contributed to this report.