Did you ignore the warnings LAUSD ? "LA school district was warned of ransomware threat before recent shutdown " The Verge

"Even if a victim has backups, they will need weeks and months of expensive recovery and incident response that must be completed to ensure the network is safe to run fully again," he said..."

https://www.theverge.com/2022/9/9/23344349/lausd-warned-ransomware-threat-trickbot