Virgin Galactic confirmed Friday afternoon that its two-pilot SpaceShipTwo rocket had suffered an “anomaly” in flight, causing it to crash at the Mojave Air and Space Port in California. It was SpaceShipTwo’s first test in over nine months, following a change in its fuel to one derived from plastic instead of rubber.

"During the test, the vehicle suffered a serious anomaly resulting in the loss of the vehicle," Virgin Galactic said in a statement. "The WhiteKnightTwo carrier aircraft landed safely. Our first concern is the status of the pilots, which is unknown at this time."

One pilot is reported dead, and the other has suffered serious injuries, according to the California Highway Patrol. The flight was delayed and took off at 9:19 PST.

(Update: 3:28 EDT) Virgin Galactic says it is cooperating with authorities, and that while the SpaceShipTwo was lost, its carrier, the WhiteKnightTwo, had landed safely. A press conference is scheduled for 2 p.m. PDT.

"Our first concern is the status of the pilots, which is unknown at this time." Virgin Galactic said. "We will work closely with relevant authorities to determine the cause of this accident and provide updates ASAP."