SIOUX FALLS, S.D. (KELO) — The heavy snowstorm has become deadly. 

The Minnehaha County Sheriff’s Office said a county highway department employee was helping a deputy clear a roadway for travel, suffered a medical emergency and later died.

The deputy sheriff helped render aid and the plow operator was transported to the hospital but died as a result of the medical emergency, a news release said. 

The Minnehaha County Sheriff’s Office says the death was natural causes.

Authorities did not provide the name or age of the plow driver.