From https://metaculus.com/questions/17179/infrastructure-disaster-from-ai-before-2025/
As more of the world's infrastructure has major digital components, cyberattacks have the potential to become more common and lead to bigger disasters. None, however, have been directly attributed to AI systems. Non-AI cyberattacks on infrastructure include:
In May 2021, a ransomware attack on Colonial Pipeline caused widespread fuel shortages in the eastern United States. The attack, which was carried out by a group called DarkSide, forced Colonial Pipeline to shut down its operations for several days.
In August 2022, a ransomware attack took down many different parts of England's National Health Service that led to system outages for several weeks.
In Oct 2022, a DDOS attack took down several US airline websites, and was attributed to Killnet, a pro-Russian hacker group.