It’s one of the scariest scenarios imaginable when you’re on the road: You suddenly find your car is submerged in water.

What should you do, other than not panic?

Fox News Digital spoke with Tina Paff, a certified driver rehabilitation specialist for Bick’s Driving School of Southwest Ohio, about how to stay safe in the event of a submersion.

“Water submersion occurs more often than most people think,” Paff said on Wednesday.

A 2016 study from the University of Manitoba noted that every year, around 400 people die in submerged vehicles in North America — accounting for up to 10% of all drownings.

Flooding is the primary reason for these occurrences, according to Paff.

“Sometimes it involves losing control of a vehicle during a storm next to a body of water, like a river, and a car will accidentally drive into that,” she told Fox News Digital.

Then there are the rarer catastrophic events — such as the Francis Scott Key Bridge collapse in Maryland on Tuesday.

While a water submersion incident is terrifying and dangerous, Paff said that with a “calm demeanor, you can survive.” She shared tips for how to do that, should it happen.

If you know you’re heading for a plunge, the first step is to brace yourself with both hands on the wheel and be ready for the impact, Paff advised.

The first thing to do as soon as your car hits the water is to release your seatbelt as quickly as possible, she said.

The second most important thing is to get the window open.

Follow along with The Post’s coverage of the Francis Scott Key Bridge collapse in Baltimore.

The second most important thing is to get the window open.

“You will have a period of time before the water starts to fill the car,” Paff said.

“So the two most important factors are seatbelt removal and opening the front window so that you can escape.”

If someone is in your backseat and your headrest is removable, it’s best to remove that so the person can swim out the front window, the expert said.

“If you’re in a situation where the car becomes submerged quickly and there’s no time to open the window, the next best thing is to break the window,” she said.

The problem is that most people don’t have a tool in their car to break the window — which is why Paff recommends always keeping an emergency hammer close at hand.

“The other option is that if the headrest is removable, you could possibly use that to break the window,” she suggested.

If you can’t get out the window, the next approach — after unbuckling your seatbelt — would be to try and push the door open with your feet, using your heels.