OPP have not said what caused a portion of Anglesea Street near Highway 21 in Goderich to be closed Wednesday night for a police investigation.
Just before 11 p.m., police notified the public about an active investigation and increased police presence.
The street was closed between Victoria Street north and Cambria Road north. People were being asked to avoid the area.
On Wednesday night, police said their investigation was in its early stages. The street reopened just before 1 Thursday morning.
Police have not provided further information.