Two women drowned in the back of a sheriff’s van Tuesday when deputies tried to drive down a South Carolina road flooded by tropical storm Florence.

The Horry County Sheriff’s Office described the women as “detainees" but later clarified they were mental patients who had been involuntarily committed for treatment.

They were getting a routine ride from the sheriff’s office to another hospital, according to coroner Jerry Richardson. “It’s a courtesy they do,” he said. “Sometimes you do the right thing and it ends up wrong.”

He said the sheriff’s van picked up Wendy Newton, 45, and Nicolette Green, 43, at a hospital in Loris — a small town north of Myrtle Beach that lacked a mental-health ward. (A county spokeswoman said they had actually been picked up in Conway, about 20 miles southeast of Loris.)

The van was bound for Florence, about an hour’s drive northwest in good conditions. But that afternoon, in the storm’s aftermath, it wound through a treacherous maze of closed roads and floodwaters pouring off the Pee Dee River and its tributaries.

The van was only halfway to Florence by early evening, when it went underwater near Highway 76 and Pee Dee Island Road.

“They were driving through very swift water, and deep water,” Richardson said. “It took them away. It ran off the road and sank.”

In a statement, the sheriff’s office said two deputies escaped from the cab and tried to get the women out of the back. While some news reports said the women were chained up, a county spokeswoman said they were only bound by seat belts.

“Despite persistent and ongoing efforts, floodwater rose rapidly, and the deputies were unable to open the doors,” the county’s statement reads.

By the time a rescue team arrived, the deputies were stranded on top of the van. It was too late for the women.

Richardson said a diver was able to get a look at the bodies, but as of Wednesday afternoon the van and women remained submerged.

“They’re in a ditch,” the coroner said. “It’s deep, swift, dark and contaminated. You’ve got snakes, tree limbs and trash.” A dive team was assembling to extract the women as he spoke, and the county announced late Wednesday that Green’s and Newton’s remains had been recovered, though the van remained submerged.

Horry County referred questions about the incident — including whether the women had been locked in the van — to state investigators, who said they had no new information to release.

Green had lived in Myrtle Beach and Newton in Shallotte, N.C., according to the coroner. Their deaths push Florence’s toll across three states to nearly 40 victims.

“Tonight’s incident is a tragedy,” Horry County Sheriff Phillip Thompson said in a statement. “Just like you, we have questions we want answered.”

This article has been updated and corrected. An earlier version used an incorrect name for Newton supplied by authorities to the Associated Press — Windy Wenton.

Read more: