LAUREL, Ind. - The body of a 13-year-old boy was recovered Saturday in a southeastern Indiana creek, the last six people presumed to have drowned when two vehicles were swept off a roadway after torrential rainfall deluged the region’s hill country, authorities said.

The boy’s body was found Saturday morning in Sanes Creek, where the bodies of his sisters, ages 7 and 4, and the siblings’ mother, Felina Lewis, 35, of Laurel, Indiana, were recovered Friday, said Franklin County Coroner Brian Baxter. The children’s names were not expected to be released, he said.

The victims from the other vehicle were identified as Shawn Roberts, 47, and Burton Spurlock, 48. Both men were also Laurel residents.

Baxter said autopsies were pending on all six victims, but they are presumed to have drowned.

A van and a pickup truck carrying the victims were swept off a roadway into Sanes Creek late Thursday or early Friday after a bridge over the creek was partially washed out by floodwaters when the area received 2-3 inches (5-8 centimetres) of rain, officials said.

Indiana Conservation Officer Josh Thomas said the creek, a tributary of the Whitewater River, quickly surged into a torrent in the region, which has many steep ridges and valleys that are prone to flooding during heavy rainfall. It’s unclear whether the vehicles were washed into the creek at the same time or separately, he said.

“It’s terrible. It’s hard to fathom,“ Thomas told The Associated Press. “Down here, with all these hills, things flood quickly. A lot of these creeks are very small, but all of a sudden they’re big with a lot of water and a lot of water moving really fast. They go down almost as quickly as they come up.”

He said all of the victims’ bodies were found along the creek and not in the vehicles.

Laurel is about 55 miles (89 kilometres) southeast of Indianapolis.