CHESAPEAKE — The cause of two fires that destroyed historic buildings in Chesapeake last month are still undetermined, according to state officials.

On May 21, an old carriage house on Maplewood Private Drive caught fire shortly after 3:30 a.m. The fire completely engulfed the building, destroying all but a shell of brick and cut stone.

Two mornings later, a two-story mansion built in 1840 along the same road — adjacent to the other burnt structure — also went up in flames.

The once-luxurious plantation-style house was reduced to a pile of wood and ash.

The unoccupied house was put on the historic register in 1977 for its unique and intricate architecture and its historical importance. It reportedly had tunnels that ran to the Ohio River that were part of the Underground Railroad during and after the Civil War.

Chesapeake Assistant Volunteer Fire Chief Ed Webb said previously the second fire is suspicious for several reasons, most notably because the house did not have any working utilities. The carriage house had utilities.

The Division of the State Fire Marshal and the Lawrence County Sheriff’s Department are investigating the fires, but there are still no answers as to their origins or if the two are linked.

Shane Cartmill, a spokesman for the fire marshal’s office, said Tuesday the investigation into the fires is ongoing and interviews are still taking place. No further information is being released at this time.

The two buildings were some of the oldest structures in the Chesapeake community. They are situated along the Ohio River and were put up for sale recently after being at the center of ongoing legal disputes.