A Cessna 560 Citation V plane crashed in Virginia after its pilot became unresponsive while flying near the Washington DC area.
Military fighter jets were scrambled to intercept the aircraft, but the pilot did not respond.
The plane was eventually intercepted by US F-16 fighter jets and caused a sonic boom heard across the Washington DC metropolitan area.
Four people were on board the aircraft, which overshot its planned destination by 315 miles before crashing.
The National Transportation Safety Board is investigating the crash and the plane was registered to Encore Motors of Melbourne, Inc.
out of Florida.
The family members of the pilot and her daughter, granddaughter and nanny were on board and have not been found.
A pilot flying an airplane near the National Capital Region became unresponsive and US officials worked closely with federal partners to monitor the situation.
The US Capitol Complex was briefly placed on an elevated alert until the airplane left the area.
The US Secret Service said they did not alter their posture for keeping President
Joe Biden secure after the incident, and Biden was golfing at the Andrews Air Force Base golf course near Joint Base Andrews in Maryland.
The incident "had no impact on Secret Service," according to a spokesperson.
The President has been briefed on the incident.