Dan Whittington, a deputy with the Indian River County Sheriff’s Office on Florida’s east coast, was responding an unrelated call on October 8 when he noticed the delivery driver standing by the overturned, partially submerged car.

A collision with another vehicle had sent the car tumbling top-first with an elderly couple and their caretaker inside. Whittington and the driver went into the canal together, helping each other through the treacherous mud.

“I was stuck in the mud in the water,” said Whittington. “My feet wouldn’t come up and I finally got my feet free. He kind of pushed me up a little bit, gave me a lift onto the bottom of the car, and I crawled across the other side of the car.”

Afterward, Whittington forced open a front door to break out the couple.

“They were pretty shaken up, pretty frightened, all of them,” he said. “The lady in the back, I remember hearing her yell, ‘I want out of the car, get me out of the car.’ And the gentleman, he was shouting he was drowning, ‘Help, help, help.’ And the elderly woman was like, ‘Help me get out of the car.’ She said she was gonna drown too.”

All three passengers were transported to local hospitals.

About 400 people die every year in submerged vehicles across North America, accounting for 5 to 11 percent of all drownings, according to researchers Gordon Gisbrecht with the University of Manitoba and Gerren McDonald with the University of Winnipeg.

Gisbrecht and McDonald determined that the easiest time to exit a sinking car is during its “floating” phase—the 15 to 63 seconds before water reaches the bottom of the side windows. The best escape route is through an opened or broken window, pushing children out first, since it’s very difficult to get back in and rescue someone once you are out.

“I think we were all put there for a reason at the perfect time to help those people,” said Whittingon. “I’m glad we were there and it didn’t turn tragic.”