BELCAMP, Md. — Maryland State Police are investigating a deadly interstate crash in Harford County involving a bus.

Authorities say it happened around 6 a.m. when troopers from the JFK Memorial Highway Barrack responded to the scene of a single-vehicle bus crash on I-95.

A preliminary investigation indicates that the bus, carrying 24 people, was traveling northbound on I-95 when, for unknown reasons, it lost control and struck a guardrail. One passenger from the bus was pronounced deceased on the scene.

The remaining passengers were transported to Johns Hopkins Bayview Medical Center.

All northbound lanes of I-95 at mile marker 77 are closed for the ongoing investigation.

Authorities are urging the drivers to plan alternate routes while the crash investigation continues.

Police say no charges have been filed.