A man and a woman died after being rescued from two separate house fires on Saturday night, according to fire and rescue officials in Fairfax County, Virginia.

Firefighters responded at around 5:58 p.m. on Jan. 20 to the first fire in the 3800 block of Kings Hill Court in the Mt. Vernon area. The flames had extended to both floors of a single-family home by the time officials arrived, according to a Monday news release from Fairfax County Fire and Rescue.

Crews extinguished the fire and rescued one elderly man with serious injuries, transporting him to a local hospital. Officials said the man died later that evening.

The fire department determined that the fire began in the living room, but investigators are still working to figure out what caused the blaze. Officials said the Red Cross is assisting with additional displaced occupants who were not home at the time of the fire and that the flames resulted in approximately $475,500 worth of damage.

Units responded to the second fire around 11:23 p.m. in the 8200 block of Mockingbird Drive in the Annandale area. Crews worked to extinguish the heavy fire on the roof of the two-story home, the department said in a news release Monday.

One female occupant was rescued and transported to a local hospital with serious injuries. The department said she succumbed to her injuries and died at the hospital.

The fire was caused by an electrical issue and started in the attic, according to officials. The blaze caused approximately $639,913 worth of damage.

In both cases, neighbors reported the fires after observing flames from outside the homes.

Both of the occupants’ causes of death are pending autopsies and toxicology reports. Neither was publicly identified by fire officials. No firefighters were injured while battling these fires.