What did the Russians use to take out this self propelled gun?

 

#Ukraine: A Ukrainian AS-90 155mm self-propelled howitzer was destroyed by Russian forces North of Mali Shcherbaky, #Zaporizhzhia Oblast.

This is the first confirmed loss of this type, of a total of 32 donated by the UK. pic.twitter.com/4nYbF8kQAA

— 🇺🇦 Ukraine Weapons Tracker (@UAWeapons) July 3, 2023

Is the size of the crater a result of the onboard ammo cooking off or are they targeting individual weapons with damn near ballistic missiles? That crater is abnormal. I thought cooked off ammo caused things to go out and up...not down. What hit this thing!