UPDATE: Rivergate Drive was re-opened to traffic around 6 p.m., after a closure of about four hours.

Rivergate Drive between the intersections of Blue Ridge Lane and Pilgrim Trail will be closed "for an extended period of time" pending an investigation by the Wilton Police Department, OSHA, and Eversource.

According to police, around 12:30 p.m. Thursday, June 9, Wilton central dispatch received a 911 call concerning a medical emergency involving a utility worker in the area of 31 Rivergate Drive.

"A preliminary investigation shows that an employee of an Eversource subcontractor was in the process of placing a pole when one of the workers on the ground went down to the ground from a standing position for an unknown reason," a notice from the Wilton Police Department said.

Wilton police, fire, and EMS were dispatched. Wilton CERT responded also, and will be assisting with traffic control until the road is reopened. The victim was transported by the Wilton Volunteer Ambulance Corps to Norwalk Hospital.

Police said the investigation "will focus on the possibility of an electrical-related incident."