NEW YORK (CBSNewYork) — Keyless ignitions are convenient and easy — but does this new technology come with deadly consequences?

The technology behind keyless cars allows drivers to open their car doors and fire up the engine with a simple push of a button, CBS2’s Kristine Johnson reported.

“You don’t have to dig into your pockets,” George Gonzalez said. “Especially in the wintertime.”

But there’s just one problem with this popular feature: Hundreds of people a year say they’re forgetting to push the button a second time to turn the car off.

“One night I was in a rush, stepped out of the vehicle and forgot, I thought it was off — and the next morning the car was still running,” Gonzalez said.

For Gonzalez, who parked on the street, forgetfulness cost him a tank of gas. But for others, the mistake has cost them their lives.

Martis Alex is an attorney who filed a class action lawsuit against ten of the world’s largest auto makers over this issue.

“Put your car in the garage, go into your home, never knowing that your engine is still running,” Alex said.

Experts say it happens easier than you might think with today’s silent engines. You put the car in park, unload it, close the garage door and the carbon monoxide builds — eventually seeping into the home.

“There have been many instances, four in the last year, of people dying because of it,” Alex said.

Attorney Noah Kushlefsky, who’s represented five keyless carbon monoxide injuries and deaths, says the National Highway Traffic Safety Administration has spent years debating what to do about this problem.

“Hundreds of people have reported to them making this mistake of leaving the car running,” Kushlefsky said.

“Instead of having a debate, why not have the manufacturers fix the problem,” Alex said.

Alex says it’s not that difficult — a simple software update could detect when a car has been idling for too long and shut it off.

“If we have an automatic shut off so you can save you the inconvenience of a dead battery when you leave your headlights on, why can’t we have an auto shut off on an engine to save your life?” Alex said.

“Current keyless ignition system designs generally follow the recommended practices of the Society of Automotive Engineers,” the Auto Alliance, which represents many car manufacturers, told CBS2.

NHTSA says it’s still reviewing suggestions on how to fix the problem

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