In the accident in Summerfield in which a passenger on a Harley Davidson motorcycle died at a hospital, the individual has been identified as Anna Josephine Hall, 66, of Belleview.
The driver of the motorcycle, John Oliveri, 71, of Summerfield, was taken to a Gainesville hospital with serious injuries.
James Benjamin Rogers, 40, of Belleview, the driver of a 2010 Ford F-150 pickup involved in the accident, only had minor injuries, officials said.
Troopers said the motorcycle was heading southbound on U.S. 441 in the inside lane when the pickup, which was behind the motorcycle, struck the cyclists from behind, throwing both Oliveri and Hall, as well as the bike, onto a grassy shoulder.
The two on the motorcycle were not wearing helmets, officials said.
While troopers were investigating that accident, in Weirsdale, a 1998 Pontiac Bonneville driven by Wesley Martin Custer, 29, was westbound on County Road 42 when the car crossed the center line and collided head-on into a 1999 Dodge 1500 pickup truck driven by Cody J. Nolan, 18.
The pickup caught fire, but the Weirsdale resident managed to escape with non-life-threatening injuries. He was taken to a hospital for treatment.
Custer, also of Weirsdale, died at the scene.
The traffic fatalities were the 44th and 45th for the year in Marion County.