STURGIS, S.D. (NewsNation Now) — Authorities have recorded four fatalities during this year’s Sturgis Motorcycle Rally. 

The 81st annual Sturgis Motorcycle rally began Aug. 6 and concluded Sunday. The state Department of Safety said two deaths occurred on Saturday, NewsNation affiliate KELO reported on Sunday.

A 66-year-old man was killed Saturday morning when he lost control of his motorcycle in Sturgis, hit a curb and fell off the motorcycle. He was not wearing a helmet and was pronounced dead at the scene.

Hours later, a 51-year-old motorcycle driver failed to negotiate a curve on U.S. Highway 14A just east of Sturgis. As a result, he and his 46-year-old female passenger were both thrown from the motorcycle. She was pronounced dead at the scene. The driver sustained non-life-threatening injuries. Neither were wearing helmets. 

Saturday also saw five crashes involving serious injuries, bringing the total number of injury crashes during the rally to 60.

Meanwhile, South Dakota Highway Patrol data shows arrests for drugs and drunken driving are down at this year’s Sturgis Motorcycle Rally compared to last year. 

According to the Highway Patrol, DUIs are down 14%, while misdemeanor drug arrests dropped 34% and felony drug arrests declined by 8%. 

According to the patrol, citations and warnings are up from last year. Citations climbed 20%, and warnings are up 23%. 

Earlier this week, Meade County Sheriff Ron Merwin said that his deputies are generally looking past enforcing possession of small amounts of marijuana. 

The use of medical marijuana became legal in South Dakota on July 1, but the state is still developing regulations. In addition, Gov. Kristi Noem is challenging the constitutionality of legalizing recreational marijuana, with the matter currently before the state Supreme Court.

The Associated Press and NewsNation affiliate KELO contributed to this report.