An early morning fire caused substantial damage to a home in the town of Bergen and left one firefighter suffering from Thursday’s sweltering heat.

Two people were inside the home when the fire started and both got out safely, according to Emily Dobeck, deputy chief of the Mosinee Fire Department. While neither occupant was hurt, one firefighter was transported to a hospital when overcome by heat, Dobeck said.

Two cats also were in the home; one was rescued by firefighters but the other died in the blaze, firefighters said.

Initial reports from the Marathon County Sheriff’s Department pointed to a lightning strike as the cause of the fire. The actual cause remains unclear, though the fire originated in the basement, according to the deputy chief.

No property surrounding the home at 985 S. County O was damaged, and firefighters were uncertain whether the extent of damage to the single-family structure will allow the owners to return, Dobeck said.

The deputy chief said she was unsure of the family’s immediate plans for shelter.

This story first appeared in the Wausau Daily Herald on July 21, 2016.