Elon Musk cracked jokes as users of his $44 billion acquisition prepped for the twilight of Twitter

• Twitter's offices abruptly closed down Thursday night amid reports of impending mass resignations.
• But Elon Musk tweeted through the chaos.

Elon Musk kept tweeting even as the walls appeared to be coming down around him.

The tech billionaire was cracking jokes online as the future of Twitter hung in the balance Thursday night after the company's offices abruptly shut down and employees reportedly began to quit en masse.

Company officials told employees that all Twitter buildings were temporarily closed and that their badge access would be revoked, Insider confirmed Thursday. The reason behind the unexpected closure was that Musk was concerned employees would "sabotage the company," Platformer's Zoë Schiffer reported.

As a deluge of mournful hashtags trended on Twitter Thursday evening, including #GoodbyeTwitter, #RIPTwitter, and #TwitterDown, Musk was keeping things light.

"How do you make a small fortune in social media?" he tweeted. "Start out with a large one."

Musk bought Twitter for $44 billion in October after months of legal back-and-forths. He quickly began cleaning house and firing top Twitter executives.

In his first company-wide email earlier this month, Musk told employees that they could no longer work remotely and would need to prepare to promptly return to the office. He later clarified that they could remain at home with their manager's approval.

He also offered the company's remaining 4,000 or so employees a choice: commit to Musk's "extremely hardcore" version of "Twitter 2.0" or be considered part of a voluntary layoff.

When the deadline rolled around Thursday at 5 p.m. ET, less than half of the company's staffers had chosen to sign up for Musk's new vision, Insider's Kali Hayes reported, taking the billionaire by surprise.