An RTD bus was involved in a major crash that closed the northbound lanes of Parker Road just south of Orchard Road for more than two hours, the Arapahoe County Sheriff’s Office said.

Parker Road reopened to northbound traffic about 8 a.m., according to the Colorado Department of Transportation.

Multiple “serious injuries” were reported by the Sheriff’s Office.

An RTD spokesperson said the bus was in service at the time of the crash and passengers were on board, but it is unknown if any of them were injured.

Deputies advise drivers to use alternate routes as the Colorado State Patrol investigates the crash.

Bus route 483 was detoured away from the crash scene, the RTD spokesperson said.