The live demonstration of Tesla’s new Cybertruck went awry on Sunday night in Hawthorne, California, wiping at least three quarters of a billion dollars off Elon Musk’s net worth. The electric vehicle maker unveiled on Sunday night its new electric pickup truck but things did not go as planned.

It took Tesla months to build the hype around its futuristic Cybertruck before its official unveiling on Dec. 1. Unfortunately, it took only one failed debut for Musk’s net worth to drop by $768 million and Tesla’s share price by 6%, and for Wallstreet to lose its confidence in the new truck. It all happened when Elon Musk demonstrated the Cybertruck’s “shatterproof” design but ended up shattering the vehicle’s armor-glass windows into pieces.

“You want a truck that’s really tough, not fake tough,” Musk said during his live demonstration of the new angular vehicle. “You want a truck you can take a sledgehammer to, a truck that won’t scratch, doesn’t dent,” he added.

In his bid to prove that Cybertruck was that tough, Musk then asked a Tesla designer to take a sledgehammer to the Cybertruck’s door. While the sledgehammer did no damage to the vehicle, things took a turn for the worse when Musk directed the designer to throw a metal ball at the Cybertruck’s armor-glass windows and the windows fell off. “Oh my f***ing God!” a surprised Musk exclaimed.

The designer reached for a second ball and threw it at the second window with less force, but the second window ended up just as shattered as the first. “For a weird little reason, it broke now and I don’t know why,” said an embarrassed Musk. “We’ll fix it in post,” he added.

As expected, the botched demonstration led to a significant plunge in Tesla’s share price on the same day. Musk, the 41st richest person in the world, also saw his net worth drop to $23.6 billion after the demo. The mishap reportedly left Musk in an upset and dumbfounded situation.

Meanwhile, Deutsche Bank analyst Emmanuel Rosner said the shattering of the Cybertruck’s unbreakable glass window during the live demonstration was not a good start for Tesla. “We believe there are important unanswered questions to be able to assess potential buyer interest in the model, and whether or not this could attract commercial fleets or remain a consumer vehicle,” Rosner said in a statement.