A hospital said a woman's heart surgery went well. Then she bled to death into a garbage can, lawsuit claims.

At first, a doctor at St. Mark's Hospital told Donnamay Brockbank's family that her open-heart surgery had been completed without a hitch.

The 62-year-old had arrived at the hospital in Millcreek, Utah, on July 11, 2018, to remove a metal heart device that was causing an allergic reaction. During the procedure, a surgeon had inserted a cannula, a long, thin tube and needle, into one of her veins near her neck, using a cardiopulmonary bypass machine to pump blood into a reservoir that re-entered through her femur.

"The doctor comes out and says to the large family there that it's a successful surgery," Rand Nolen, one of the family's attorneys, told The Washington Post. Brockbank's heart was beating on its own, at that point, and the surgical wound had already been closed.

But moments later, Brockbank was in "severe distress," according to a complaint filed earlier this month. Her vitals were collapsing and no one could figure out why.

For 40 minutes, the medical professionals pumped seven units of blood into Brockbank - almost doubling the amount of blood typically found in a human body. Still, her heart was failing. Where was all that blood going?

Into the garbage can on the floor below the operating table, according to Nolen - soon causing Brockbank to bleed to death.

While the surgeons had removed the line into her femur, the other line from her neck had not been clamped, according to the complaint. Another medical professional had placed the disposable reservoir it fed into the garbage - a fact that none of the doctors noticed as her vital signs crashed, her family alleges.

About an hour and a half after telling Brockbank's children that she was OK following the surgery, the surgeon returned to tell the family that its matriarch had died.

"They thought everything was fine and then [the surgeon] comes out and tells them she's died," Nolen said. "What he told them was, 'This is on me.' At that point, he wasn't entirely sure what happened."

Now, the family has sued the hospital and the doctors overseeing the surgery for multiple claims of negligence.

Officials with St. Mark's did not return a request for comment late Sunday.

"We want to express our deepest condolences to Donnamay Brockbank's family for their loss," the hospital's CEO, Mark Robinson, said in a statement to the Salt Lake Tribune. "Unfortunately, we are unable to comment on any pending litigation. That said, we continuously seek to learn from every patient situation to improve the quality and safety of the care we provide in our operating rooms and throughout the hospital."

The lawsuit, filed July 10 in the Third Judicial District Court in Salt Lake City, claims that "Brockbank bled until her heart could no longer beat" because of the blood - both her own and the seven additional units - that was streaming into the garbage can instead of into her body. Brockbank's family, who say they have suffered "emotional anguish" and are seeking an amount to be determined at trial, claim that the doctors at St. Mark's "failed to comprehend that Donnamay was bleeding to death right in front of their eyes."

"It's horrifying because it's one of these things you would expect in a battlefield situation where no one knows what's going on and there's chaos," Nolen said to The Post. "But this was at what's supposed to be a first-degree hospital in the United States of America in a major metropolitan area. You don't anticipate this kind of inattention."

About two days after their mother's death, Nolen said, the family was told by hospital employees of the reservoir of blood that was found underneath the operating table. From there, Nolen said he and the family's legal counsel concluded that her death would have been avoided if the doctor, or any of the medical staff on hand, had simply clamped the line that streamed the blood into Brockbank.

"It boggles the mind, with how experienced this team was, that nobody would catch such a simple oversight," Rhome Zabriskie, another of the family's attorneys, told the Tribune.

It was not just the decision-making that's been called into question. When Nolen and outside medical professionals pored over the hospital's records regarding the removal of Brockbank's heart device, the documentation for the procedure was "as poor, if not poorer, than you would find in a Third World country, and fall well below the standard of care for medical record keeping," according to the lawsuit. Key details, such as the whereabouts of the assistant surgeon following the initial surgery, were missing entirely, Nolen said.

A mother of four children and several stepchildren, Brockbank devoted her life to her family, especially her 23 grandchildren. She was an active member in the Church of Jesus Christ of Latter-day Saints in Vineyard, Utah, about 40 minutes southeast of Salt Lake City, and loved art and traveling, according to her obituary. In interviews with NBC News, her son Brad, 39, remembered his mother's warm spirit.

"She would give herself to anybody that needed it," Brad said. "She was the kindest, most generous woman that I've ever known."

Her eldest son, Bart, 41, echoed his mom's effect on others.

"Her smile was always able to make you feel better," he said.

Nolen said the family still wonders why their mother bled to death during a standard procedure.

"Until there is a resolution and better answers, the wound is going to stay open," the attorney said. "They are looking to get some sort of conclusion so they don't have to relive it all the time."