Virgin Galactic CEO George Whitesides vowed to find out the cause of the crash of its SpaceshipTwo space tourism rocket today over the southern Mojave Desert and to move forward.

Of the two tests pilots, employed by SpaceShipTwo manufacturer Scaled Composites, on board the rocket, one died and the other was sent to a hospital with “major injuries,” an official said.

Scaled Composites was conducting the test and it included a new fuel formulation that had been tested numerous times on the ground,” said Kevin Mickey, the president of Scaled Composites, at a press conference this afternoon in Mojave, California.

Officials declined to speculate on the cause of the accident.

Virgin Galactic’s Richard Branson was en route to Mojave, California, and was due to arrive Saturday morning, officials said.

“The future rests in many ways on hard days like this,” Whitesides of Virgin Galactic said.

He said Richard Branson’s Virgin Galactic will try to understand the cause of the accident, and moving forward “is what we’ll do.”

Scaled Composites conducted the test, which began at 9:20 a.m. Pacific Time today. WhiteKnightTwo, the aircraft carrying SpaceShiftTwo, released the space tourism rocket at around 45,000 feet at 10:10 a.m., and two minutes later officials from the Mojave Air & Space Port realized there was an “anomaly,” said its CEO, Stuart Witt.

Witt added that he saw no indication of an explosion, but realized things were amiss when certain other things weren’t taking a place.

WhiteKnightTwo eventually returned to its base with no injuries on board the aircraft.

“The test community is very small. We are human and it hurts,” a Scaled Composites official said, referring to the fatality and serious injuries to a second pilot.

He added that there was a large debris field in the Mojave Desert. The precise condition of the second pilot wasn’t known, although officials said he was transported to the hospital and had major injuries.

Prior to the press conference, Virgin Galactic, which had been slated to take passengers on SpaceShipTwo for sub-orbital space flights starting early in 2015, issued the following statement:

“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.”

SpaceShipTwo would have carried up to six passengers, but only the two pilots were on board the test flight.

Photo Credit: The debris field for Virgin Galactic's SpaceShipTwo in the Mojave Desert in California. Associated Press