Allison McManus wears a necklace containing a picture of her older half-sister, Andria Ziegler. And in her heart, she carries important words to live by - words Andria once told her younger sibling.

"She told me to always smile and be happy." said 10-year-old Allison, who often went to the movies, the mall or lunch with Andria and her four other big sisters.

PVCC professor was investigated in 2002

Listen to Michael Todd's 911 call

But no one in Ziegler's large, tightknit family is smiling or happy.

They are grieving "Andie's" death and trying to move on with their lives as best they can while awaiting answers from Phoenix police detectives.

"Andie used to give me hugs," said Andria's stepfather, Doug McManus, who raised her since she was 7.

"There will be odd times during the day I think I should be getting a hug, and Andria isn't there," he said.

Ziegler, 19, a freshman at Paradise Valley Community College, was pronounced dead at John C. Lincoln Deer Valley Hospital about 3 a.m. April 20, less than 30 minutes after paramedics discovered her in a comatose state in the home of her psychology professor, Michael Todd.

Ziegler's cause of death is pending toxicology results, according to the Maricopa County Medical Examiner's Office, and police are investigating the case as an unknown death.

Police have said they will not release any more information on the case until the toxicology reports are back, something that can take several weeks, according to the medical examiner's office.

Police said drugs may be a possibility, something Andria did not have a history with, her parents said.

Todd, 51, who has worked at Paradise Valley Community College since 2000, is not a suspect in Ziegler's death, and no suspects are being pursued, according to Phoenix police Detective Stacie Derge.

However, college officials began efforts on May 8 to fire Todd for having an inappropriate relationship with Ziegler and failing to report the incident to his supervisors. Todd has been unavailable for comment.

His attorney, Michael Roth, has not returned telephone calls from the Tribune.

It is not known at this time whether Todd plans to appeal his termination.

Ziegler, one of Todd's students for the last two semesters, had confided to one of her friends that Todd had been asking her out, according to John Hughes, the family's private investigator looking into her death.

Ziegler was enamored with Todd as a professor, the family said, and about a week before her death, she came home and asked her parents if she could date a "35-year-old," the age Todd allegedly told her he was, according to her parents.

"We told her 'absolutely not,'" said Ziegler's mother, Kimberly McManus. "We told her that would be inappropriate. She told us he was a professor and had his own private practice. Call me naive, but we thought, 'He's a 35-year-old grown man, he's not going to go out with his 19-year-old student.' Boy, was I wrong."

While standing in Hughes' shaded front yard in north Phoenix, Doug and Kimberly McManus and five of Andria's seven siblings described her as a caretaker, someone who always wanted others to be happy.

"She could brighten a room," Kimberly McManus said. "She was one-of-a-kind. She was a chronic communicator, and would always call us."

"We called her 'Free Meal' because she made sure she never missed a meal with the family. She was always home for dinner, and we joked with her about that. She was vivacious, bright and loved life," her mother recalled.

Andria, whose favorite place to eat at was My Big Fat Greek Restaurant, gave one of the commencement speeches last spring when she graduated from Metro Center Academy, an alternative high school, Kimberly McManus said. Andria also looked out for her younger sisters. She often would coax Athena, 12, into finding enough spare change around the house so they could spend it at Starbucks.

Andria also had called Amanda, 13, about midnight, less than three hours before her death to check in, Amanda said.

"She was calling to check in and see how things were," Amanda said. "She was OK then. She said she was going to hang out with some friends at Applebee's."

Andria also was best friends with sisters Ashley, 21, and Aimee, 17, with whom she had worked as a hostess at the Pointe in Tyme restaurant at the Pointe Hilton Tapatio Resort in north Phoenix until December.

Andria quit her job then so she could go to school full time, family members said.

Andria hoped to work as a child psychologist or as a physical therapist and considered caring for the elderly.

Ashley Ziegler said she hung Andria's picture from the rearview mirror of her car.

"She was like one of my best friends, and I'm really going to miss her," she said.

"A part of me thinks that she is still here and it's really, really hard. ... Andie's not here and she's actually never going to come home again," Ashley said.

Ziegler's family also questions how Todd could have remained on the job after a female student filed a sexual harassment complaint against him in 2002. Todd was accused of making sexual advances on that student in his office and initiated inappropriate touching with her, but the college did not receive enough evidence to confirm or deny the incident, according to PVCC documents. Todd denied any inappropriate activity with that woman in 2002, according to college records.

According to authorities, Todd made the 911 call about 2:34 a.m. April 20 to report an unresponsive female about 20 years old inside his home.

Todd claimed not to know who Ziegler was when paramedics arrived, according to police, and he did not provide paramedics with any forms of identification.

Police told McManus they received Ziegler's car keys, cell phone and wallet containing her driver's license from Todd's attorney.

"It's indescribable, what we're going through," said Kimberly McManus. "I miss hearing her voice. My first day back to work, I realized it was after 10 o'clock, and Andria hadn't called me. Then, I realized she wouldn't be, and that was it."