A ramp and the westbound lanes of Interstate 70 in Frederick County remained closed this morning after a fertilizer truck overturned on the roadway Wednesday night.

The vehicle, a tractor-trailer loaded with fertilizer, rolled over on the ramp from Monocacy Boulevard to westbound I-70 around 8:55 p.m. The driver and passenger of the truck were injured and transported to Frederick Memorial Hospital, according to Maryland State Police.

The ramp was closed, as were all lanes of westbound I-70 at South Street, due to the crash investigation and clean-up efforts. The Maryland State Highway Administration has set up a detour, directing drivers on westbound I-70 to take Exit 55 (South Street) to Monocacy Boulevard to Route 85 and back onto I-70.

Authorities said they don’t know when the ramp and lanes will reopen.