Automakers would be required to install technology on new vehicles that alerts exiting parents to check for children in the back seat under legislation introduced in Congress in response to deaths of children left behind in hot cars.

Lawmakers say more than 800 children forgotten in vehicles have died from heatstroke in the United States over the last two decades.

The bill would require the National Highway Traffic Safety Administration to write new rules withIN two years mandating the introduction of “a distinct auditory and visual alert” to remind drivers to check the back seat. It would also require a study to assess the feasibility of retrofitting existing vehicles with the system.

Rep. Jan Schakowsky said 48 children died of heat stroke last year. She noted that many newer vehicles alert drivers if they leave their keys behind. “You should get a warning if you leave a child in the car.”

The Alliance of Automobile Manufacturers, representing General Motors Co, Toyota Motor Corp, Volkswagen AG and other major automakers, said it will “carefully review any legislative proposals keeping in mind that fewer than 13% of new car buyers have a child six years old or younger.”

The group noted, “It takes about two decades for a technology to reach all the passenger vehicles on our roads. Greater public awareness saves live today.”

The proposal is sponsored by a number of lawmakers including Senate Commerce Committee Chairman Roger Wicker, a Republican, the committee’s top Democrat Maria Cantwell and Representative Jan Schakowsky, who chairs a subcommittee overseeing auto safety that held a hearing on the issue on Thursday.

Schakowsky said 48 children died of heat stroke in cars last year. “In the vast majority of those cases, the adult did not realize the child was inside the car. It’s not enough to educate parents about the risks,” she said.

She noted that many newer vehicles alert drivers if they leave their keys behind. “You should get a warning if you leave a child in the car,” she added.

GM in 2016 introduced a safety system to remind drivers to check for children in the rear seats. Triggered by back doors of the car being opened at the start of the trip, the system, in use on some vehicles today, alerts drivers with a unique honking sound to check the back seat at their destination.

The system does not detect the presence of a child in a car seat.

The Senate version was introduced late Wednesday, while the House version will be introduced in the coming weeks.