Ragdoll NPC's continue to lag game after being destroyed

so I have a bunch of NPC’s that when they die (happens ALOT) I set them to enable physics and go ragdoll, then after like 10 seconds, the game destroys them. but the only problem is that the game is still for some reason calculating the physics and is making everything lag. any idea how to fix this?

Edit: I have tried disabling simulated physics right before they get destroyed but it has not really done anything.