Did hackers steal $460 million from a bitcoin exchange?

Could you please clarify the situation surrounding the alleged hack of a Bitcoin exchange? Are we certain that hackers were indeed responsible for the disappearance of $460 million in cryptocurrency? What security measures were in place to prevent such a breach, and how were they bypassed? What steps are being taken to recover the funds and ensure the safety of users' assets in the future? I'm particularly interested in hearing about any ongoing investigations or legal actions being pursued in response to this incident.