Sad news today: Alaska Senator Ted Stevens died in a plane crash Tuesday.

Former Alaska Sen. Ted Stevens, 86, died in a plane crash in southwest Alaska, a spokesman for the Stevens’ family confirmed to ABC News today.

Five of the nine people who were on board died in the plane crash that occured Monday night near Dillingham, Alaska, and two were seriously injured. Rescue crews reached the wreckage Tuesday morning, the National Transportation Safety Board (NTSB) said today.

Former NASA administrator Sean O’Keefe was also a passenger on the plane. O’Keefe is the current chief executive of the U.S.-based division of defense contractor, EADS North America, and was in charge of NASA from 2001 to 2005.

A source at NASA told ABC News that O’Keefe and his son Kevin both survived the crash but were severely injured.

The other four who died in the crash were Theron “Terry” Smith, 62 of Eagle River, Alaska, the pilot; William “Bill” Phillips Sr.; Dana Tindall, 48 of Anchorage, Alaska; and her 16-year-old daughter, Corey Tindall, also of Anchorage, the Alaska Department of Public Safety said.

What a horrible tragedy for the families of all of the souls lost on board. Please keep the families in your thoughts and prayers.