Two 7-month-old twin girls were found dead in a Lindenwold apartment on Wednesday after their mother called 911 and told dispatchers her twins had turned "purple."

What caused their deaths remains unknown. That information is "pending" as the Camden County Medical Examiner performs further tests, the county prosecutor's office said Wednesday afternoon.

The infants' mother called for help around 8 a.m. and sobbed as the dispatcher talked her through performing CPR on the babies, according to a copy of the 911 call the prosecutor's office provided. The call lasted more than six minutes.

"Oh my God, my babies," the mother, whom authorities did not name, said. "My twins, they're like purple. They're not breathing."

The mother said she and the infants were in her bedroom, and that she had attempted CPR before calling 911. The dispatcher, unable to understand how many minutes the distraught mother said she had tried CPR, asked, "You've tried for 15 minutes?"

"I've tried, no, they're not breathing at all," she said.

Asked if anyone was with her and the babies, she said "just my friend."

When an emergency responder arrived minutes later and asked when the twins had gone to bed, the mother replied, "Like 6:30. They both fell asleep."

Alice Shields, 74, who lives a few doors down from where the infants were found, called them "beautiful babies" and held back tears as she described them Wednesday.

"I can't believe this," she said. "I just can't believe this."

Shields said she saw the infants with their mother at The Pines apartment complex last week and said hello.

"She said everything was fine, they were doing well," Shields said.

Other neighbors in the large complex, which has two-story apartment buildings spread out below pine trees, saw police Wednesday morning but said they didn't hear much else.

Anthony Rivera, 37, who has a 3-year-old son, called the infants' deaths troubling.

"This is terrible," he said. "I hate hearing stuff like this."

Staff writer Julie Shaw contributed to this article.