HARTFORD, Conn. – Jonathan Metz had been trapped for two days in his basement with his left arm stuck in a broken furnace. Smelling rotting flesh, he decided that amputation was his only hope.

So the 31-year-old fashioned a tourniquet near his shoulder and began cutting. He made it almost all the way through, but wasn’t able to free himself.

He was rescued Wednesday when worried friends called police, and firefighters cut the furnace apart.

Doctors gave the account of Metz’s three-day ordeal at a news conference Thursday. They said the attempted self-amputation probably saved his life, preventing the infection in his gangrenous arm from spreading to the rest of his body.

“There was a little bit of fat that remained and he was in and out of consciousness,” said Dr. Scott Ellner, Metz’ surgeon at Hartford’s Saint Francis Hospital and Medical Center. “It sounds like maybe there was a nerve there that prevented him from completing the amputation.”

Metz, who lives alone, had been working to replace the boiler fins on his furnace Sunday when his arm became trapped.

A friend, Luca DiGregorio, said that he and other friends grew worried when Metz did not show up for work and missed a Tuesday night softball game.

Metz also did not answer the doorbell when DiGregorio stopped at his home Wednesday, where he said he saw Metz’s beagle, Porsche, “yipping at the back door.” DiGregorio called police, who found Metz in the basement.