Two residents of upper Montgomery County were killed in southern Maryland Saturday afternoon when their tandem bicycle was struck by a vehicle from behind.

John Henrik Fauerby, 64, and Lynne Frances Rosenbusch, 58, both of Clarksburg, were riding the bicycle north on Tobacco Road in Calvert County about 3 p.m. when the crash occurred near Tobacco Lane in the Chesapeake Beach area, the sheriff’s office said.

A Jeep came up from behind and struck the bicycle in the rear. throwing off both Fauerby and Rosenbusch, the sheriff’s office said.

Rosenbusch died at the scene, and Fauerby died at Calvert Memorial Hospital, according to the sheriff’s office. Public records indicated that they owned a house together in Clarksburg.

The driver of the Jeep was arrested, the sheriff’s office said.

In a statement, the office said Catherine Frances Lyon, 62, of Huntingtown, Md., was charged with driving under the influence and homicide by motor vehicle while under the influence.

The crash remained under investigation.

Rosenbusch’s LinkedIn page indicated that she had a long career as an auditor with the federal government. She had worked for the Department of Health and Human Services and for the Consumer Product Safety Commission.

He was identified as a software engineer who had worked for the Computer Sciences Corporation.

Itappeared that she was also a member of a Frederick County bicycle club. Online information indicated that he was also an avid cyclist.

It is about 70 miles from Clarksburg to Chesapeake Beach and it was not clear whether the two had ridden all the way on their bicycle.