Three people from Allegheny County, including a young boy, died Wednesday evening when the minivan they were riding struck a tree in Brady Township, state police said.

Kimberly A. McLaughlin, 31, of McKees Rocks was driving south on Route 173 just after 6 p.m. when the van crossed into the northbound lane and traveled into a yard.

The vehicle hit a tree stump and then slammed into a tree, state police said.

McLaughlin and her front seat passenger, Terry W. Cramer, 42, of Coraopolis, died at the scene. The couple’s son, Terry W. Cramer Jr., 3, was taken to Butler Memorial Hospital, where he died a short time later.

McLaughlin’s two other children, ages 1 and 11, who were in the van, were seriously injured and taken to Children’s Hospital of Pittsburgh of UPMC.

Police continue to investigate the crash.