Police in Anne Arundel County and in southern Maryland are investigating unrelated fatal crashes that claimed three lives Friday night and Saturday, including that of a 14-year-old boy, according to authorities.

The latest accident occurred about 7 p.m. on Saturday in Great Mills in St. Mary’s County. Maryland State Police said a motorcycle crashed in a single vehicle accident on Flat Iron Road, near Highway to Heaven Lane.

Police did not release details on how the accident occurred but said they were reconstructing the circumstances. They did say speed contributed to the crash.

Police said that when troopers arrived the driver was alert and talking, and that his injuries were not considered life threatening.

He was flown by Maryland State Police MedEvac helicopter to Maryland Shock Trauma enter in Baltimore, were police said his conditioned worsened and he was pronounced dead at 9:42 p.m. on Saturday. His name has not yet been released.

Another accident about 10 p.m. Friday claimed two lives in Anne Arundel County. Police said the driver of a black 2012 Ford Focus heading south on Patuxent River Road in Davidsonville lost control on a curve and struck a tree.

The driver, Carrie Lynn Desmond, 36, of Davidsonville, was pronounced dead at 6:30 a.m. Saturday at Maryland Shock Trauma Center, police said. A 14-year-old passenger, who was not identified but lives at the same address as the woman, died at the same hospital at 1:15 p.m. on Saturday.

Anne Arundel County police said their investigation is continuing. Anyone with information is urged to call the Traffic Safety Section at 410-222-8573.