New London — The family of a 19-year-old Montville woman who sank to the bottom of the pool at Ocean Beach Park and later died in the hospital has filed a wrongful death suit, claiming carelessness and negligence on the part of the park’s manager and its lifeguards.

Lobsang Dolma, a Tibetan-American and 2014 Montville High School graduate, had spent Aug. 12, 2015, with her aunt, uncle, nieces, nephews and friends at Ocean Beach Park. They were ending their visit at the swimming pool when sometime before 3:30 p.m. Dolma sank beneath the water unnoticed by any of the six lifeguards stationed around the pool, according to the lawsuit filed Aug. 1 by New London Attorney Maxine L. Matta in New London Superior Court.

Bystanders at the pool at some point noticed “a shadow at the bottom of the deep end and began signaling or shouting that someone was in the bottom of the pool,” according to the suit.

The suit alleges that one of the lifeguards who had noticed the shadow said she thought it might be a test like one received in lifeguard training school and swam down to find Dolma. That same lifeguard came back up and “shouted for help to get the person out of the deep end of the pool as she couldn’t do it by herself,” the suit alleges.

Dolma was pulled to the surface by at least two lifeguards, who began lifesaving measures. Dolma was partially revived but never regained consciousness.

A doctor treating Dolma at Yale New Haven Hospital indicated in an Aug. 13 report that Dolma had been submerged for three minutes, the suit claims. The decision was made by her family on Aug. 13, 2015, to disconnect life-saving devices.

Dolma was pronounced dead with a diagnosis of “brain death secondary to cardiac arrest secondary to hypoxic respiratory arrest secondary to drowning,” according to the suit.

The suit names lifeguards, the park’s manager, the management company and the city, which owns the property.

Among a host of allegations is that Centerplate Inc., the management company that runs Ocean Beach, “failed to diligently oversee the hiring of well-trained and conscientious managers and lifeguards which is the overriding duty it owed to the patrons and invitees of Ocean Beach.”

The suit alleges lifeguards failed to adequately watch the swimmers and did not react quickly enough when bystanders started shouting about a person in the bottom of the pool.

Attorney Matta said Dolma was living with her uncle in Montville at the time, as her parents did not want her growing up in New York City, where they lived and worked. She was enrolled at Eastern Connecticut State University with future plans to obtain a business degree and pursue a career in the corporate world.

“All I can say is she was a very sweet and very smart girl,” Matta said. “It was just a horribly tragic event that happened. Her family was very shocked and very saddened, of course.”

No dollar amount is attached to the suit. Matta said the suit is an attempt to gain justice and help the family pay for medical, funeral and other associated expenses.

And while Centerplate, and not the city, carries the liability for incidents at the park, Matta said the city “chose this management company” and in an incident “this egregious ... a liability escape clause shouldn’t count.”

Ocean Beach Manager Dave Sugrue declined to comment, citing the pending litigation.

g.smith@theday.com