A passenger on a motorcycle was killed and the driver was critically injured Saturday in Howard County when the motorcycle crashed, county police said.

The motorcycle was on the ramp from Route 175 west to Route 29 north in the Columbia area at around 5:16 p.m. when the driver lost control and hit a guardrail, the police said.

Both the passenger and the driver were thrown off. The female passenger — later identified by police as 26-year-old Kristen Renee Snyder of Elkton — died at the scene, police said. A 33-year-old man operating the motorcycle was taken to a hospital. He remained in critical condition, police said Sunday.

Police were trying to determine the cause of the crash.