Caledon OPP are investigating a serious collision that happened on Highway 10.
At around 6:30 Friday morning, OPP were called to a collision on Highway 10 between Olde Base Line Road and Charleston Sideroad.
Two people were airlifted to a Toronto-area trauma centre, three other people had minor injuries.
Highway 10 was closed in both directions for several hours while technical collision investigators and reconstructions were on-scene.
Anyone with information is asked to contact the OPP at 1-888-310-1122 or Crime Stoppers at 1-800-222-TIPS (8477).