The home of former Virginia Gov. and U.S. Sen. Chuck Robb suffered more than $1.6 million in damages in the fire that sent Robb and his wife, Lynda, to the hospital, Fairfax County Fire and Rescue said Thursday.

The fire department said the Robbs were alerted to the fire by their working smoke alarm system and reminded county residents that working smoke alarms save lives.

No firefighters were injured while working to put out the fire on the 600 block of Chain Bridge Road in McLean.

The cause of the fire is still under investigation. The fire department estimated that it could be several weeks before the cause is determined.

Luci Baines Johnson, Lynda’s sister, told WTOP that her brother-in-law, Chuck Robb, was hospitalized with burns but has since been released. Her sister suffered smoke inhalation. Lynda Bird Johnson Robb is the eldest daughter of former President Lyndon Johnson.

The home has an estimated value of $3.4 million, according to Fairfax County property records.

Tom Johnson, a longtime family friend and spokesman, told WTOP that the Robbs had a collection of political memorabilia, some of which had been handed down from President Johnson and his wife, which was priceless and irreplaceable.

The couple had lived in the home for nearly 50 years.

WTOP’s Alejandro Alvarez contributed to this report.