An Ohio animal rights activist took her life last week, along with 31 rescue dogs, the Moreland Hills Police Department said.

WOIO reported the death of Sandra Lertzman, 62, who was the Executive Director at the Animal Rights Foundation.

Police say they found her dead in her car -- which was running in the garage -- and 31 dead dogs that had been trapped inside with her.

Investigators found prescription vials in the vehicle and a suicide note inside the house, CNN reported.

According to Sgt. Janet Boehler, a friend discovered Lertzman's body. It is unclear how long Lertzman and her pets -- all small dogs -- had been dead before they were found. The woman was last seen alive November 3.

On their website, the Animal Rights Foundation gave a reason for why she may have taken the dogs' lives with her:

"She obviously feared that upon her death, these abused dogs would be placed in harm's way," the website says. "Sandy spent countless hours every day taking care of each dog and their specialized problems with her love that she offered."

Only one of the dogs managed to survive, escaping the car and breathing through a gap in Lertzman's garage. That dog is now with Lertzman's husband, Rick, WKYC reported.

"She wanted to continue to rescue and save these animals but, unfortunately, nobody can take care of 30 animals, properly, by themselves," said Gina Lutes-Finley, Director of Dogs Unlimited Rescue.

Lertzman also left behind 20 cats. They were unharmed.