Elon Musk Says He May Start Building A Tunnel Under L.A. As Early As Next Month

Elon Musk has already made a rocket that can land on its end. He's also set to unveil a fully self-driving Tesla in the near future. So, when he says that he's over L.A. traffic and that he intends to build an underground tunnel to bypass the gridlock, how can we doubt him?
Though...really? I mean, is this something you can just do? Even if your bank account is massive? If Musk's tweets—sent early Wednesday morning—are any indication, he's totally going to do it. He says he may start as early as next month, and that he'll start digging right by the SpaceX headquarters in Hawthorne.
Exciting progress on the tunnel front. Plan to start digging in a month or so.
— Elon Musk (@elonmusk) January 25, 2017
Starting across from my desk at SpaceX. Crenshaw and the 105 Freeway, which is 5 mins from LAX
— Elon Musk (@elonmusk) January 25, 2017
One person asked the question that's still brewing in our minds:
So you were serious? Like seriously serious?
— Clay Ellis (@clay_ellis) January 25, 2017
Yup
— Elon Musk (@elonmusk) January 25, 2017
But what about earthquakes?
In some places that sounds like a great idea, but in earthquake southern Cali? Sort of scary thinking about what could happen.
— Jeff Schader (@JeffSchader) January 25, 2017
Earthquakes tend to have the biggest effect on the surface, like waves on water. That's why LA can have a (lame, but getting better) subway.
— Elon Musk (@elonmusk) January 25, 2017
As noted at Business Insider, Musk had brought up the tunnel idea before. In 2015, he appeared on Neil deGrasse Tyson's "StarTalk" radio show and said that tunnels would be a far more efficient option than, say, flying cars. "And it would always work, even if the weather is bad. It would never ice up, and it would never fall on your head," said Musk.
So the idea had been floating around for a bit. But, apparently, it was one fateful December day that pushed him over the edge:
Traffic is driving me nuts. Am going to build a tunnel boring machine and just start digging...
— Elon Musk (@elonmusk) December 17, 2016
But can you, like, really just start digging a massive tunnel in the ground? We called Hawthorne's City Manager, as well as its Director of Building and Safety, but neither have responded to our messages yet. We also called Metro about it. "We don't really know anything else about it, aside from the tweets," said Director of Public Relations Joni Goheen, adding that "he certainly wouldn't be able to do it without the proper permits."
SpaceX representatives have also yet to get back to us.
[Update 8:10 p.m.]: A representative of SpaceX wrote back to LAist to say that the company had no comment on the matter.