This wasn’t a launch, just a pre-launch test but something went very wrong and the rocket and the communications satellite it was supposed to carry into orbit were completely destroyed. Fortunately, the launch pad had been cleared for the test and no one was hurt.

After the initial explosion you can see the payload crash to the ground. (Note: There is audio but it is several seconds behind the video, so watch your volume.) If you continue to watch after the initial explosion, it appears the fire is dying down but then, around 3:40 in this clip, there is another large explosion.

The Associated Press reports the explosion shook buildings four miles away:

The explosion — heard and felt for miles around — dealt a severe blow to SpaceX, still scrambling to catch up with satellite deliveries following a launch accident last year. It’s also a setback for NASA, which has been relying on the private company to keep the International Space Station stocked with supplies and, ultimately, astronauts…

Facebook spokesman Chris Norton said his company was “disappointed by the loss, but remain committed to our mission of connecting people to the internet around the world.” Founder Mark Zuckerberg was in Kenya on Thursday, discussing internet access with government officials.

Space X and company founder Elon Musk tweeted about the disaster:

Update on this morning's anomaly pic.twitter.com/1ogCMPCY44

— SpaceX (@SpaceX) September 1, 2016

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

TechCrunch says today’s explosion could push back Space X’s launch schedule by months, but the real problem is how this disaster will raise concerns about the company’s reliability:

SpaceX has made a business out of being one of the cheapest launch providers in the game. They’re considerably cheaper than, for example, United Launch Alliance, one of SpaceX’s direct competitors.  While ULA doesn’t make their prices public, by some accounts customers can save 40 percent by choosing SpaceX over ULA.

But with ULA’s higher price tag comes reassurance that your payload will get where it needs to go. ULA has had a near-perfect launch record since 2006 with only two partial failures, while SpaceX has experienced two large failures in the past 15 months.

Moments ago, Elon Musk tweeted that some work he was doing for his other company, Tesla, would be postponed:

Finishing Autopilot blog postponed to end of weekend

— Elon Musk (@elonmusk) September 1, 2016