Heavy rains from Monday night and Tuesday morning washed away a culvert near Fort Yates, which is just a few miles north of the South Dakota border.
According to family members, Trudy Peterson was heading from her home in Mobridge to her job in Fort Yates. They say she probably never saw the road was washed away because it was dark and raining.
A U.S. Postal worker from Mobridge also died in the flooding.