It's best practice to immediately lock someone out from all accounts if they are leaving on bad terms. You don't want them to be sending nasty emails to customers or to delete company data. It almost never happens but sometimes someone snaps and creates a big mess.

You should come and maybe bring something nice for the people you enjoyed working with. Make sure you have a talk with the project managers boss and tell him why you are leaving. Furthermore you should act professional so don't involve your colleagues. It's nasty but it's between you, him and his boss. Your colleagues will figure it out anyway.

Best of luck finding a new job!