75 -year-old man trapped in his car for 14 hours: 'It was terrible.'

A Cleveland man said he got into his convertible 2006 Cadillac one morning last month to go for a ride and instead got trapped inside the vehicle for 14 hours after he lost electrical power and couldn't figure out how to manually open the power-locked doors.

Peter Pyros told ABC News in an interview that the vehicle had started up fine when he turned the engine on two weeks prior to the incident, and said that when he again approached the car and clicked his key fob, the Cadillac doors unlocked as expected.

Pyros said he got in and tried to start the car -- which he said has only about 12,000 miles on it -- but it wouldn't start. So he tried to get out but said the doors were locked. He clicked his key fob and nothing happened, so he changed the batteries in the key fob and tried again, without success.

Pyros, 75, said he began to panic. He had no cell phone handy to call for help. He lost track of time.

“I tried desperately to get out of the car, and I tried to punch the window first," Pyros said. "That didn't work. I tried to kick the window out with my two feet. That didn't work. Then I was screaming for help.”

A spokesperson for General Motors, which manufacturers Cadillacs, told ABC News that all Cadillacs come equipped with a mechanical door release -- which is described and identified in the car owner's manual, as well as a feature guide that comes with the vehicle.

Pyros said his owner's manual was inside the house. He broke into a severe sweat and began to yell for help.

“I was screaming the whole time, 'please help me, help me!' I was screaming, pounding on the windows, screaming."

He said he began to struggle and his breathing became labored.

“It was terrible,” he told ABC News.

Pyros, who lives alone, said he passed out. Eventually he gave up hope.

“I realized I was in the car, and I wasn't going to get out -- that this was a reality, that I was going to die,” he said.

Pyros said he was very much at peace knowing that he was going to die, and he was ready to let his relative know the cause of his death.

Pyros said he wrote a note to his nephew, to be found later, telling him, "I'm dying a terrible death."

Whenever he heard a noise, like a passing car, Pyros said he would scream and pound on the car windows, calling for help. By nightfall, he grew exhausted by his efforts, and again lost hope of a rescue.

“When it got dark, I figured, well, that was it. It's final. There's no way. Nobody's going to save me. I'm going to die,” Pyros said he thought to himself.

At around 11 p.m. that night, Pyros noticed a light moving around in his yard, and was thrilled to realize it was his neighbor, a firefighter. The neighbor told Pyros that he had tried to call him about an hour earlier to tell him that his garage door was open and there was noise coming from inside.

Around midnight, after what he described as 14 hours trapped in the Cadillac, Pyros was freed and transported to a local hospital.

Tom Wilkinson, spokesman for General Motors, said in a statement that all GM cars are equipped with "a mechanical, (non-electrical) method for occupants to unlock and open the doors should the vehicle lose power."

“The Cadillac XLR has a mechanical door release handle on the floor beside each of the seats, which is described in the owner’s manual and feature guide GM provides with the car.”

“Drivers of any vehicle should familiarize themselves with the owner’s manual for their vehicle, including the door lock section, and follow up with their dealer or GM’s customer assistance center if they have any questions,” Wilkinson said.

Byron Bloch, a court-qualified auto safety expert based in Potomac, Maryland agreed in an interview that the cars all contain manual exit options. But he suggested that a clearly-labeled emergency exit handle, with a warning label on the sun visor, could help prevent similar situations in the future.

“One is the information about the manual emergency relief handle and a warning label on the sun visor,” Bloch told ABC News over the phone interview.

He also suggested the prospect of “an energy reserve module which would provide electrical energy to the door latch system even if the main battery system is not functioning.”

Bloch said that it was lucky for Pyros that the car was "in the garage not out in the hot sun."

“If the same thing happened and the car had been outside on, you know, a hot, sunny day, the man could have easily...been a fatality.”