Quite a sad event in the development of a space program by the private sector. We have previously featured Rutan in this post, explaining the development of a civilian space program.

Blast at desert spaceport kills 3 – CNN.com: A third person died Friday from an explosion at a rocket test pad operated by a private company in California’s southern Mojave Desert, according to the nursing supervisor at Kern Medical Center in Bakersfield.
The explosion, which occurred Thursday at the Mojave Air and Space Port in Mojave, California, initially killed two people and critically injured four others

The six were employed by Scaled Composites, an aerospace development company founded 25 years ago by Burt Rutan, the aerospace engineer who designed the first plane to fly nonstop around the world without refueling.
According to Rutan, the blast occurred during a test involving nitrous oxide flowing through fuel injectors. A source said the workers were testing components of a new rocket motor for SpaceShipTwo, which is a spaceship being built for Virgin Galactic, Richard Branson’s space tourism company.