“The preliminary investigation suggests the victim drowned while swimming,” Major Michael S. TenEyck wrote. “The victim’s body showed no signs of foul play and was transported to the Jefferson County Medical Examiner’s Office pending an autopsy to determine an official cause of death.”

Craig Dorfman, her manager, confirmed Mara’s death to The Washington Post on Tuesday.

“Mary was one of the finest actresses I ever met,” Dorfman said. “She was electric, funny, and a true individual, and devoted to her family. Everyone loved her. She will be missed.”

A family spokesperson told Deadline that Mara was staying at the summer home of her sister, Martha Mara. The property is near the St. Lawrence River, which separates the United States and Canada.

Mara was a celebrated character actress with more than 80 screen credits to her name. She’s best known for her time in the ’90s as a recurring character on NBC’s hit show “ER,” playing patient Loretta Sweet, and her stretch as Inspector Bryn Carson, a main character on CBS’s “Nash Bridges.” She later played recurring characters in the Showtime shows “Dexter” and “Ray Donovan.”

Born on Sept. 21, 1960, in Syracuse, Mara studied at San Francisco State University and Yale before starting her acting career. Roger Mara, her brother, told the San Francisco Examiner in 1996 that they were both encouraged to pursue acting after seeing “their mother’s flair for the dramatic.”

Mary Mara’s first credited role was in the 1989 made-for-TV movie “The Preppie Murder,” according to her IMDb page. After appearing in the 1992 Billy Crystal film, “Mr. Saturday Night,” Mara broke through on “ER” at a time when the NBC show was the hottest prime-time medical drama on television. She appeared in nine episodes between 1995 and 1996, playing Sweet, a former prostitute diagnosed with cervical cancer.

The recurring spot on “ER” helped catapult Mara into a main cast role on “Nash Bridges,” appearing in 23 episodes in the first two seasons between 1996 and 1997. After appearing on such shows as “NYPD Blue,” “Ally McBeal” and “Law and Order,” Mara landed recurring roles as Valerie Hodges on “Dexter” in 2009 and Mrs. Sullivan on “Ray Donovan” in 2013.

She most recently appeared in the 2020 film “Break Even.”

Dorfman told The Post that the outpouring of grief he’s received since Sunday has been “extraordinary.” Some of the people who had worked with Mara over the years went on social media to remember a colleague described as the consummate professional.

Actor and director Jon Lindstrom recalled working with Mara during a theatrical run of “In Heat” in Los Angeles at a time when, he said, she had undergone chemotherapy for cancer.

“She was plowing through the aftereffects of Chemo,” Lindstrom wrote, saying Mara’s death left him “crushed.” “Brave, brilliant, Uber-talented. Earth will be much less-colorful without her.”

Screenwriter Bob Saenz posted a black-and-white photo of Mara, whom he said he worked with for “2 great years.”

“This the Mary I remember,” Saenz tweeted. “Consummate pro, funny, sharp, kind, a first class human being. She was kind enough to participate in a table read of one of my earliest scripts.”

He added, “RIP Mary. You’ll be missed.”

Mara is survived by stepdaughter Katie Mersola, sisters Martha Mara and Susan Dailey, brother-in-law Scott Dailey and nephew Christopher Dailey, according to Variety.

The investigation into Mara’s death is ongoing, police said.