"I just couldn't understand how she walked out happy and fine and just died all of a sudden," her daughter, Amber Waddell, told WJBK .

Walters, 46, had sarcoidosis, COPD, diabetes, asthma and high blood pressure. She was also on oxygen.

When Walters' sister, Crystal Cutright, took her to  Dr. Rana Rabban to have the teeth removed, the medical assistant who took her vital signs was concerned about her heart rate of 130 beats per minute.

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"The dentist came in, ready to do the procedure," Waddell said. "The dental assistant said, 'I am waiting for her heart rate to come down.' The dentist said, 'We're fine,' and the procedure starts."

The dentist pulled 16 of the 18 teeth before telling Walters that she would stop for the day.

"She was talking to April. She said, 'I think you need to go to the doctor and get your heart checked on,'" Waddell said.

According to Waddell, the dentist stepped out but returned to say, "Yeah, ma'am, when you leave here you should probably take her to the doctor and get that checked out. Her heart rate's kind of high."

Cutright was worried as she worked to get Walters and her oxygen tank into the car.

On the way, Walters said, "I can't breathe," according to Waddell.

Cutright went back into the dentist's office for help, thinking that her sister's oxygen tank was low.

Waddell said that although the staff came out with more oxygen, no one knew how to perform CPR.

"When the dentist came out she started yelling, 'I told you to take her to the hospital,' so I yelled back at her, 'I have to get her in the car in order for that to happen,'" Waddell said.

Waddell said an ambulance was called but it was too late.

"A 46-year-old woman should not die in the parking lot of a dentist's office," Waddell said.

An  investigation into Walters' death has been launched.

"Our hearts go out to the family and our prayers," dentist Chad Wise said. "We are looking at everything that happened that day."

Waddell set up a GoFundMe page to help with funeral costs. It has surpassed its $2,000 goal.