The idea emerged after Jonathan "Yoni" Shimshoni and a team of aspiring inventors in Israel watched a television documentary about victims trapped on the upper floors of the World Trade Center on Sept. 11, 2001.

Shimshoni recalled seeing the towers ablaze and thinking, "This is nuts. This shouldn't have to happen."

The team came up with a $1 million escape device with expandable cabins that could be lowered like lifeboats outside a high-rise in distress.

A prototype tested in Tel Aviv drew praise from politicians, public safety experts and the landlord of a Manhattan skyscraper, who offered his property for a pilot program.

Then Shimshoni received a discouraging letter from the city's Office of Emergency Management. He was told, in short, that the project was unworthy of the necessary building permits.

The letter was a blow to Shimshoni's company, Escape Rescue Systems. But the CEO — a 55-year-old former Israeli military officer with a doctorate in public policy from Princeton University — insists it wasn't fatal.

"If there's anyplace that should revolutionize high-rise safety, it's New York City," he said recently at his Manhattan office, inside a 30-floor building where he still hopes to test the system.

Shimshoni believes public opinion and political pull could change the city's position.

He also says he has the backing of advocacy groups for the disabled, which believe his system would improve the chances of survival for people in wheelchairs. And he has received letters of endorsement from city council members, including Yvette Clarke, chairwoman of the fire services committee, who checked out the prototype on a trip to Israel.

"I personally rode on the system and was amazed," Clarke wrote.

The company's Web site features a video shot in Tel Aviv during a demonstration of the device. It shows the system being lowered with cables from a rooftop crane.

Once on the street, it expands to form five cabins that, like an external elevator, lift firefighters up the side of the building, where they help people evacuate through windows.

Each cabin can hold up to 30 people, meaning 150 people could be evacuated during eight-minute deployment cycles. He estimates the system would have saved hundreds of lives at the World Trade Center on Sept. 11.

In a letter dated Feb. 6, OEM commissioner Joseph Bruno said the city is open to "exploring creative solutions" for high-rise evacuations. But, he said, an analysis by fire, police and building officials raised too many concerns about Shimshoni's system.

Among the city's concerns: There would be confusion over who would operate the system during an emergency; using windows as escape routes can help a fire spread; passengers in the cabins risk passing floors immersed in flames; and the system would be prone to the Titanic effect — chaos over who would be first in line for a limited number of spots in each cabin.

Shimshoni acknowledges the city's concerns are legitimate, but "if you want to be sure how to address them, there should be a pilot program," he said.