Twitter users were in a frenzy of speculation on Friday afternoon that the website might be forced into an immediate shutdown after hundreds of employees reportedly decided to quit.

There were other reports of security staff booting employees out of Twitter offices, and offices being locked shut.

The events followed a strongly worded ultimatum from the social media company’s new owner, Elon Musk, on Thursday (Australian time). He demanded Twitter staff either work “long hours at high intensity” or leave.

“Going forward, to build a breakthrough Twitter 2.0 and succeed in an increasingly competitive world, we will need to be extremely hardcore,” Mr Musk said in a leaked email.

“This will mean working long hours at high intensity. Only exceptional performance will constitute a passing grade.” 

It appeared by Friday afternoon that many employees had not taken up Mr Musk on his offer, with dozens publicly declaring that they had not ticked the yes box.

He reportedly met top employees and engineers in a last-ditch attempt to try to convince them to stay.

In a poll on the workplace app Blind, 76 of 180 people chose the answer for “Taking exit option, I’m free!”.

In a private chat on Signal with about 50 Twitter staffers, nearly 40 said they had decided to leave, according to one former employee.

Twitter was flooded with an onslaught of ‘salute’ and blue heart emojis on Friday afternoon as many employees seemingly announced their departure. 

The mass exodus has also already begun to wreak havoc with the site’s functionality, with inside sources telling CNN the platform was beginning to slow by later on Friday.

Monitoring site Downdetector said the number of outages had begun to skyrocket on Friday morning, with hundreds reported each hour.

The Verge editor Alex Heath said multiple employees had come forward to say that the odds of Twitter “breaking” imminently were “very high”. 

Hashtags #RIPTwitter, #TwitterDown and #Twitter2.0 were all trending internationally on Friday afternoon.

Many tweets had an end-of-days vibe – to the tune of ‘If Twitter dies, let this be my final tweet’ – with users sharing final thoughts, images and memes.

Many users also promoted their Mastodon and Instagram accounts, eager to keep followers if Twitter did go offline.