Entertainment TV 'ER' Actress Mary Mara's Cause of Death Revealed New York State Police confirmed their findings to PEOPLE days after Mara died while swimming in New York's St. Lawrence River over the weekend By Kelly Wynne Kelly Wynne Kelly Wynne has been a TV writer at PEOPLE digital since 2021. Her work has been seen in Newsweek, where she acted as a reality TV and true-crime writer, Atwood Magazine and her mental health blog, The Chronically. People Editorial Guidelines Published on June 29, 2022 11:32AM EDT Mary Mara's cause of death has been determined. New York State police confirmed to PEOPLE that Mara died of asphyxiation — or suffocation — due to drowning. "The Jefferson County Medical Examiner's Office performed a post-mortem examination on the decedent and determined that the decedent's manner of death was an accident, due to asphyxiation, due to warm water drowning," NYSP Troop D Public Information Officer Jack Keller said. On Tuesday, TMZ reported that investigators thought Mara, who was 61 at the time of her death, could have slipped and hit her head while getting out of the river — which may have caused her to fall back in and drown. They specifically noted alleged "face abrasions" found on her body. PEOPLE confirmed the report was inaccurate, with police stating, "There were no signs of any trauma to Mary's body when she was found." ER Actress Mary Mara Dead at 61 After Apparent Drowning in NY River: 'Everyone Loved Her' Matthew Simmons/WireImage Mara died while swimming in the St. Lawrence River in Cape Vincent, New York, on Sunday morning. Investigators confirmed that foul play has been ruled out. "The preliminary investigation suggests the victim drowned while swimming," they wrote in the statement. "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. Mara's rep, Craig Dorfman confirmed the ER and Criminal Minds actress's death in a statement to PEOPLE on Monday. He said she was "one of the finest actresses I ever met." "I still remember seeing her onstage in 1992 in Mad Forest off-Broadway," Dorfman said. "She was electric, funny, and a true individual. Everyone loved her. She will be missed." Dale Midkiff and Mary Mara in Love Potion #9. Everett Mary Mara's Family Remembers Gifted ER Actress Who 'Just Missed Stardom but Always Played for Winning Teams' Mara appeared in recurring roles on a handful of TV series, including Criminal Minds, Nash Bridges, NYPD Blue, Law & Order, Ray Donovan, The Practice, Gideon's Crossing, Star Trek: Enterprise, Lost, Dexter and Shameless, as well as appearances in Ally McBeal, Judging Amy, The West Wing, 7th Heaven, Monk, Nip/Tuck and Bones. A line from her obituary states that Mara, "just missed stardom but always played for winning teams." Updated by Dory Jackson Dory Jackson Dory Jackson is an Associate Editor for PEOPLE's digital TV team. While at the brand, she's had the opportunity to interview a long list of celebrities, from Kate Hudson to Pierce Brosnan to Billy Porter. She has also helped recap popular TV shows like 'The Real Housewives of Beverly Hills,' 'Sister Wives' and 'Vanderpump Rules.' The New York-based Maryland native graduated from Randolph-Macon College in May 2016 with a focus on Communication Studies and Journalism. She came to PEOPLE in March 2021 after working at a number of major news companies, including Newsweek and Us Weekly. learn more