Elon Musk's dreams of building a high-speed steel-tube transit network that would theoretically make train and short-haul airline travel obsolete appear to be dead. Hyperloop One, founded in 2014, is shutting down.

In one of Musk's many side projects upon which hundreds of millions of dollars have been spent, Hyperloop One began as Hyperloop Technologies, with Musk going so far as to build a test track for the concept outside Las Vegas and attract investment from Dubai.

As Bloomberg reports, the company raised $450 million since its founding nine years ago, and had 200 employees as of early 2022, most of them based in Los Angeles.

But the company is fully shutting down and laying everyone off, per Bloomberg, liquidating assets — including that test track near Vegas — and the few remaining employees overseeing the asset sale have been told their employment ends December 31.

As The Verge puts it, "Whoever buys the test track in the Nevada desert will have one hell of a Slip ‘N Slide if they want it."

Briefly known as Virgin Hyperloop, when billionaire Richard Branson was briefly toying with a similar transportation concept, Hyperloop One has been backed by DP World, the Dubai-based conglomerate, since 2016.

This pod- and steel-tube-based transit concept was, of course, Musk's brilliant answer to California's high-speed-rail woes, and in one of his fits of invention he wrote a white paper in 2013 outlining how he would solve things. Musk imagined tubes on raised pylons that would act like the pneumatic tubes at old banks, shuttling pods of people at unheard-of speeds, and theoretically making the trip from San Francisco to Los Angeles in 30 minutes.

The concept was likely far too expensive and not scalable for the masses, and would have just been something rich people got to use like the Concorde. And, the one and only human test conducted on the test track, in 2020, reached a speed of 100 miles per hour — about one-seventh of the imagined possible speed.

As The Verge puts it, the company was "perpetually strapped for cash," and several harassment lawsuits and allegations against executives could not have helped.

So, will Musk's Boring Company be next? It, too, was founded in a hurry after Musk got frustrated with all the traffic in L.A., and imagined everyone zipping around in underground tunnels. A test tunnel has been constructed in — where else? — Las Vegas, but last we saw it just allowed some Teslas to move between some downtown hotels at relatively slow speed.

Below, a visual reminder of what SpaceX and Musk imagined a Hyperloop tunnel would look like, back in 2015.