From Virgin Galactic:
STATEMENT FROM VIRGIN GALACTIC
Virgin Galactic’s partner Scaled Composites conducted a powered test flight of SpaceShipTwo earlier today. During the test, the vehicle suffered a serious anomaly resulting in the loss of the vehicle. Our first concern is the status of the pilots, which is unknown at this time. We will work closely with the relevant authorities to determine the cause of the accident and provide updates as soon as we are able to do so.
Sending our prayers to the pilots and their families.