A woman was rescued by police after her phone in her pocket accidentally answered a call from a telemarketer who heard her being attacked.
Chamille McElroy, a worker at a Nevada call centre heard the woman begging for her life on the other end of the phone. She asked her supervisor, Tina Garcia, to listen in to the domestic dispute.
Ms Garcia told News 8 in Las Vegas: "She (Ms McElroy) said, 'I don't think this is a joke. Something's happening. I think this lady is getting hit.'"
"The young lady on the other end of the phone never said hello. There was just a horrible whimper."
After hearing her plead with her attacker with the words "please don't kill me" they alerted authorities to the incident 900 miles (1,450km) away in Oregon.
The telemarketers stayed on the phone so the attack could be recorded for evidence.
"We were not going to hang up the phone," said Ms Garcia. "As far as I was concerned, and as far as the people in that room were concerned, we were the only lifeline she had."
Describing the scene, Linn County Sheriff's Office said: "When deputies arrived on scene a female was heard calling for help, while a male voice could be heard saying, 'quiet.'"
Police forced their way into the home to find 33-year-old Walter Ruck still assaulting the woman, who was trying to escape.
Ruck was charged with fourth-degree assault, menacing and strangulation.
Investigators said the woman, who has not been identified, did not realise that the phone in her back pocket had picked up a call and that help was on the way.