McCoy went to the University of Pittsburgh where she earned a bachelor's degree in marketing and then went to the University of Phoenix in Philadelphia, where she earned her MBA, her mother said. She was the first person in her family to earn an advanced degree, said her mother.

"My whole family is proud of her," said her mother as she broke down on the telephone. "She was very much accomplished. She had a real good personality."

She had a brother, who is about to join the U.S. Air Force and two half-siblings, said her mother, a long-time U.S. Postal Service employee.

JoAnn McCoy said she last spoke to her daughter yesterday afternoon when they talked about the family. Her daughter told her she had planned to stay home last night.

The two were "very close" and talked to each other about three or four times a week. She was the woman's only daughter and was born on Easter Sunday in 1979.

"I asked her, 'Was she going out' and she said, 'Mom I do stay home sometimes,' " her mother said. "She was always on the go and always doing things and she was involved in a lot of organizations."

Later, she texted her daughter at about 8 p.m. Chicago time and her daughter told her she was home relaxing. She found out today that she had gone out with a female friend.

JoAnn had texted her daughter pictures of herself from her cell phone and Shantel texted back a response where she good-naturedly chided her mother, 'Mom, you love posing for the camera.' That's the last time we contacted each other," her mother said.

Firefighters found the woman in an elevator on the 12th floor. The doors were open.

Fire officials have not yet determined the cause of the blaze, Roccasalva said, and that the cause likely wouldn't be determined until Monday. But fire officials do not believe the origin to be suspicious, he said.

Two firefighters were among the injured in the blaze. One was taken from the scene in fair-to-serious condition and the other was taken in good-to-fair condition, Roccasalva said. One of the two firefighters suffered exhaustion and the nature of the other firefighter's injuries wasn't known, Roccasalva said. Neither of the injuries is serious, he said.

Six other people were taken to area hospitals in fair-to-serious condition, he said. He said their injuries involved smoke inhalation.

About 150 firefighters responded to the 2-11 alarm fire. An Emergency Medical Services Plan 2 was also called, which calls for 11 ambulances to the scene.

The EMS Plan 1, which calls for six ambulances to the scene, was upgraded after more people suffered from smoke inhalation, Roccasalva said.

Residents displaced from the building were being kept warm in Chicago Transit Authority buses staged a block away or in a neighboring building's lobby, which was holding between 60 and 70 people, Roccasalva said.

Fire was blowing out the windows in the unit when firefighters arrived, he said.