Nassau police say a 17-year-old attempted to cross Prospect Avenue and Kinkel Street around 6:30pm Sunday when he was hit by a car.

A witness told News 12, "I almost got run over! I stopped traffic and started yelling at people."

The witness wished to remain anonymous but explained that she'd been enjoying an outdoor barbecue with her family when a teen ran through her driveway and into the street. After the teen was hit, she grabbed a someone’s cellphone, she said, to call 911 as she raced to his side.

“I started…saying you’re going to be OK, 911 is on the way. They airlifted him from the school right here, Park Avenue. They were going to go in an ambulance, but I guess it was too serious,” she said.

Nassau police confirm a helicopter was used to get the teenager to the hospital. They say he is in critical condition.

Police say 10 minutes prior to the accident on Prospect Avenue, a 44-year-old man was hit by a truck about a mile away on Old Country Road.

News 12 has been told that the man was brought to the hospital but died from his injuries.

Police say both crashes are under investigation and that drivers in each accident remained at the scene.