Lisa Pond was playing basketball with her three children when she collapsed from an aneurysm on the first day of a 2007 anniversary cruise ship vacation.
But after the 39-year-old was rushed by ambulance to a Florida medical center, she fought for her life alone.
Her partner of 18 years, Janice Langbehn, said she was not allowed to see Pond for eight hours as she lay dying, and their children were never given the chance to say goodbye.
She said pleas to be at her partner's deathbed were not granted because the Lacey, Wash., couple were lesbians.
Langbehn has sued Miami's Jackson Memorial Hospital and three medical professionals, alleging they "ignored" her needs and that of their legally adopted children and prevented her from making healthcare decisions.
"No one should die alone," Langbehn told ABCNews.com.
Langbehn said a social worker at the hospital informed her, "I need you to know this is an anti-gay city and a anti-gay state, and you are not going to get to see her or know her condition."
"I felt like I was being put on notice," said Langbehn, now 40 and a social worker herself. She immediately called a friend to fax health care proxies and a durable power of attorney but the hospital disregarded the documents.
The hospital, through its lawyers, denied that their social worker made any such comment and said that saving Pond's life was the doctors' top priority at the busy trauma center that serves the entire county. They said the couple was treated no differently than any other family in such circumstances.
The lawsuit, filed in the U.S. District Court in Southern Fla., alleges that the hospital staff was "motivated by anti-gay animus."
"From the moment Langbehn and the children arrived at Jackson Memorial Hospital, they encountered prejudice and apathy," the suit claims.
Langbehn is being represented by the gay activist group Lambda Legal, which said the case could determine the way hospitals treat not only gay and lesbian patients, but unmarried heterosexuals and single people who rely on friends.
"Hospitals have policies that define how patients are treated," said Lambda's lawyer Beth Littrell. "Hospitals are to treat patients with dignity and not discriminate and allow the patients to define their own families."
But, with same-sex marriage legal in only five states, gay couples can receive inconsistent access to hospital visitation and decision-making rights, according to the Gay and Lesbian Medical Association.
And in Langbehn's case, even though the hospital may have open visitation, gatekeepers can interpret those policies differently.
"Due to a patchwork of state laws and differing hospital policies across the country, there are still many challenges in guaranteeing equal health treatment for the LGBT [lesbian, gay, bisexual, transgender] community," he told ABCNews.com.
Pond had been the stay-at-home mother for their four adopted children, one of whom was not with them on vacation because he is living in a facility for disabled adults.
The family had just eaten lunch while the ship was still in port when Pond collapsed on the top deck while taking photos of the children, ages 9, 11 and 13.
Pond was rushed by ambulance to the Ryder Trauma Center at Jackson Memorial and the rest of the family followed in a taxi, arriving at the hospital at 3:30 p.m.