Two separate Charlotte crashes less than eight hours apart Thursday left two men in their 70s dead.

The first crash, which killed 70-year-old Boyd Jasper Sawyer and injured his passenger, happened around 7 a.m. on Wilkinson Boulevard in west Charlotte.

Charlotte-Mecklenburg police said Sawyer was driving a 1998 Subaru Forester when his vehicle hit a concrete median near the Boyer Street intersection. The Subaru plowed across the median, hitting two trees and overturning.

Sawyer died at the scene. His passenger, 62-year-old Darlene Margaret Chastain, was taken to Carolinas Medical Center with life-threatening injuries. Her condition was not available Thursday night.

Around 2:30 p.m. Thursday, a 74-year-old man was killed in a wreck in south Charlotte's SouthPark area.

Police said a woman driving a 2007 BMW 328i had stopped at a stop sign on Simsbury Road as she waited to make a right turn onto Fairview Road, just outside the Foxcroft shopping center. That's when a 2008 Acura TL traveling at a high speed struck her car from behind, police said.

The impact forced the BMW into Fairview Road, police said, and the Acura continued across Fairview and ran into a tree along the street.

The Acura's driver, identified as Wolfgang Kretzschmar, was pronounced dead at the scene. The other driver was not hurt.

Investigators in the morning crash were trying to determine what might have caused Sawyer to hit the median. It's also unclear why Kretzschmar didn't stop before he slammed into the stopped car in the SouthPark area.

Witnesses are asked to call the Charlotte-Mecklenburg Police Department's Crash Investigation Unit at 704-591-2525.