I was playing on a server and i threw an enderpeal at a nether portal (in the overworld) (in spawn chunks if it matters, i didnt check).
The result was the server crashing and then the chunk of the portal block it hit resetting and the portal block in the nether resetting the chunk

1. throw enderpearl at a portal ON A SERVER
2 see results, halving the portal (as you can see in the screenshot)