Medical examiners will determine what ultimately killed a teenager who survived a botched heart-lung transplant but died two days after receiving a second set of organs.

An autopsy was planned Monday on the body of Jesica Santillan, the state medical examiner's office said. A lawyer for the 17-year-old's family said an autopsy was appropriate.

"We just want to make sure we know what the cause of death was," attorney Kurt Dixon said Sunday. "If there's going to be legal action down the road, you want to have a definite cause of death. You don't want to speculate about that."

Family and friends were planning memorial services for the teenager on Tuesday, one public and another private, said Mack Mahoney, a family friend and Jesica's chief benefactor. He said he believed the family, who was in seclusion, would return her body to their home country of Mexico for burial.

Jesica, whose own heart had a deformity that kept her lungs from getting oxygen into her blood, died on Saturday.

She never regained consciousness after her first heart-lung transplant, which her body rejected because the organs didn't match her blood type. Doctors at Duke University Medical Center in Durham said they didn't check the compatibility before the surgery began Feb. 7.

By the time a matching set of organs was found and placed in her body early Thursday, she was near death.

The new organs performed well, but Jesica's brain had swelled and was bleeding Friday. She was declared dead after more than a day without brain activity.

Dixon said Duke doctors took Jesica off life support before her family could contact other physicians to get a second opinion on her condition.

Dr. James Jaggers, the transplant surgeon, said in a taped statement released Saturday by the hospital that he had hoped Jesica would be "one of those lucky few" awaiting heart-lung transplants who actually receive the surgery and do well.

"Unfortunately, in this case, human errors were made during the process" to match the organs with the patient, he said. "I hope that we, and others, can learn from this tragic mistake."

Jesica's family had paid a smuggler to bring them from their small town near Guadalajara, Mexico, to the United States so the teenager could get the medical care, relatives have said.