- Michelle Trachtenberg was found dead on Wednesday morning. She was 39.
- She began her acting career as a child star and is best known for "Buffy" and "Harriet the Spy."
- Trachtenberg's famous friends and former costars paid tribute to the actor.
After Michelle Trachtenberg's death on Wednesday morning, celebrities and fans are paying tribute.
The NYPD told Business Insider that Trachtenberg had been found dead in a luxury apartment in Manhattan near Central Park. No cause of death has been given, and authorities said they're not treating the death as suspicious.
Trachtenberg, who began acting in commercials at age 3, had a decadeslong career in Hollywood, appearing in memorable films like "Harriet the Spy" and "EuroTrip" and TV series like "Buffy the Vampire Slayer" and "Gossip Girl." As the news of her death spread, her famous friends and former costars shared their reactions and heartfelt messages online.
Rosie O'Donnell said she wished she could've helped Trachtenberg.
In a statement to Us Weekly, O'Donnell, who played the beloved nanny of Trachtenberg's character in her 1996 film debut "Harriet the Spy," called the younger actor's death "heartbreaking."
"I loved her very much. She struggled the last few years. I wish I could have helped," O'Donnell told the publication.
Shawn Ashmore called Trachtenberg an incredible person.
Ashmore and Trachtenberg dated in the 2000s. In his post about her death, he called it an "incredible loss."
"Incredibly sad to hear about Michelle's passing. She was an incredible person and I will always remember the years we spent together fondly," he wrote. "She was loving, quirky and would never pass up a law and order SVU marathon:) My condolences to her mother Lana and sister Irene!"
David Boreanaz sent prayers to Trachtenberg's family.
Boreanaz played the vampire Angel, the longtime love interest of Buffy Summers on "Buffy the Vampire Slayer" and was a series regular on the first three seasons of the show before departing for his own spinoff.
Trachtenberg joined the series as Buffy's sister Dawn Summers in season five.
