Elon Musk is moving aggressively to overhaul Twitter after his blockbuster $44 bln takeover of the messaging platform

Multiple Twitter (TWTR) employees have filed a class-action lawsuit against the company following a layoff announcement.

An email sent to staff on Thursday evening informed employees they would receive notification of their employment status by noon Friday ET, Reuters reports. The layoffs will end Elon Musk's first official week as Twitter's owner and is expected to include an estimated 3,700 employees of the company's 7,500 work force.

Musk, the richest person in the world, acquired Twitter last week for $44 billion. He has since announced some significant changes to the platform, including an $8-a-month fee for users to become verified and receive a blue checkmark, and has laid off some of the company's chief executives and dissolved its board of directors.

"If your employment is not impacted, you will receive a notification via your Twitter email," the email sent to staffers about Friday's layoffs stated, as reported by CNN. "If your employment is impacted, you will receive a notification with next steps via your personal email."

The email also informed employees that Twitter offices would be closed on Friday and access would be temporarily suspended to "help ensure the safety" of remaining employees and Twitter systems.

Employees reportedly flooded Twitter company Slack channels to say their goodbyes. Some frustrated employees took to Twitter and used the hashtag "#OneTeam."

The lawsuit filed on Thursday states Twitter violated the federal Worker Adjustment and Retraining Notification Act (WARN Act). The WARN Act requires employers with over 100 employees to provide 60 days' advanced written notice before a mass layoff "affecting 50 or more employees at a single site of employment."

"Elon Musk, the richest man in the world, has made clear that he believes complying with federal labor laws is 'trivial,'" said Attorney Shannon Liss-Riordan, who filed the lawsuit.

In a statement to CNN, Liss-Riordan added, "We have filed this federal complaint to ensure that Twitter be held accountable to our laws and to prevent Twitter employees from unknowingly signing away their rights."