By Shereen Siewert

UPDATED: At least two people died Sunday in a chain reaction crash that shut down southbound lanes of Hwy. 51 for hours.

Three vehicles were involved in the crash, reported at about 1:30 p.m. Sunday at Mile Marker 200. That spot is located between Merrill and Brokaw.

Police say a driver rear-ended another vehicle with four passengers inside. That vehicle then rear-ended a third vehicle with two passengers.

Two passengers in the second car, an 88-year-old man and a 99-year-old woman, died at the scene.

No names have been released. Additional details are expected on Monday.

A portion of Hwy. 51 closed Sunday after a serious multi-vehicle crash that left several people injured.

The crash happened at about 1:30 p.m. Sunday in the southbound lanes of Hwy. 51 at Mile Marker 200. Southbound traffic was diverted at Lincoln County Hwy. Q, routed to County Hwy. K. As of 3:20 p.m. traffic was still being diverted and the Marathon County Sheriff’s Department said the highway is closed “until further notice.”

Southbound traffic on Hwy. 51 was at a standstill for an extended period.

Police have not released details on the number of people involved or the severity of the injuries.

For updates on the detour, visit the Wisconsin Dept. of Transportation traffic page here.

This is a developing story that will be updated.