Two sisters from Utah are suing the company behind the 911 software following a life-or-death attack from an intruder.

They say the software required the dispatchers to ask a series of scripted questions before sending a police officer to the scene.

Breann Lasley says the intruder climbed through her bedroom window in Salt Lake City in the middle of the night on Sept. 23, 2015.

Breann says the intruder was repeatedly stabbing her sister, Kayli.

When she called 911, Kayli’s desperate struggle could be heard in the background, but the dispatchers never sent help, the lawsuit claims.

"I remember thinking, ‘All I need to do is call 911, if I call 911 they just need to know our address, they will send help.," she recalled.

"No help was sent,” Breann said, even after she kept screaming her address over and over again.

"It was the scariest night of our lives and we depended on those calls," she told Inside Edition. "It was every girl fears and it was happening to me."

By some miracle, an off-duty police officer on his way home from work heard their screams and came to the rescue. He shot and killed the attacker.

"We needed help, that is all we were praying for was help to be sent," she added.

The company, Priority Dispatch, told Inside Edition: “The rule we have is, ‘when in doubt, send them out.’ Unfortunately, in this situation, our system was never opened or used because they could not determine an address.”

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