This story was updated at 2:00 p.m. EDT

WASHINGTON — An explosion on a Florida launch pad early Sept. 1 destroyed a SpaceX Falcon 9 rocket and its payload, the Amos-6 communications satellite, being prepared for an upcoming launch there.

Authorities said the explosion occurred at approximately 9:07 a.m. Eastern at Space Launch Complex 40 at Cape Canaveral Air Force Station, where SpaceX was preparing to conduct a static fire test of the Falcon 9 in advance of a scheduled Sept. 3 launch. The test, which entails briefly firing the rocket’s first stage, is a routine pre-launch procedure for Falcon 9 missions.

SpaceX Chief Executive Elon Musk, in a tweet four hours after the incident, said the explosion originated around the Falcon 9’s the upper stage liquid oxygen tank while it was being loaded in the minutes before the scheduled static fire test. He said there was no information yet on the cause of the explosion.

Loss of Falcon vehicle today during propellant fill operation. Originated around upper stage oxygen tank. Cause still unknown. More soon.

— Elon Musk (@elonmusk) September 1, 2016

SpaceX confirmed both the Falcon 9 and its Amos-6 payload were lost in the explosion, but that there were no injuries in the explosion. “SpaceX can confirm that in preparation for today’s static fire, there was an anomaly on the pad resulting in the loss of the vehicle and its payload. Per standard procedure, the pad was clear and there were no injuries,” SpaceX said via Twitter.

Statement on this morning’s anomaly

— SpaceX (@SpaceX) September 1, 2016

The loss of Amos-6 is a major, untimely setback for its owner, Spacecom. With a pending sale of the Israeli satellite fleet operator contingent on the successful launch of Amos-6, shares of Spacecom’s stock fell sharply as the first reports of an explosion began rolling in.

A major user of Amos-6 was to be Facebook, the social networking company that purchased the Ka-band capacity of the satellite to provide Internet access to underserved regions of sub-Saharan Africa. “We are disappointed by the loss but remain committed to our mission of connecting people to the Internet around the world,” a Facebook spokesperson said Sept. 1.

The failure is also a setback to several other companies preparing to launch payloads on the Falcon 9, most notably Iridium. It had planned to launch its first ten next-generation satellites on a Falcon 9 from Vandenberg Air Force Base in California later in September, a launch likely to be delayed by at least several weeks while this incident is investigated.

SpaceX, which has launched eight times this year, faced a crowded end-of-the-year manifest. Nine customers were still expecting to launch on Falcon 9 before January; all but three of those missions were to lift off from Florida. SpaceX also hoped to squeeze in the first flight of its new Falcon Heavy rocket.

The failure could also have repercussions in civil and military space. SpaceX provides commercial cargo services for NASA and is developing a commercial crew system, while it is also competing for national security launches once in the exclusive domain of United Launch Alliance.

“Today’s incident reminds us all that space flight is an inherently risky business,” said Sen. Bill Nelson (D-Fla.), ranking member of the Senate Commerce Committee, in a statement issued shortly after the explosion. “As we continue to push the frontiers of space, there will be both triumphs and setbacks. But at the end of the day, I’m confident that our commercial space industry will be very successful.”

Brian Berger is editor in chief of and the SpaceNews magazine. He joined in 1998, spending his first decade with the publication covering NASA. His reporting on the 2003 Space Shuttle Columbia accident was...

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...