You have a plan should you get killed or otherwise be unable to provide the passwords. Where I work, in addition to there being more than one IT staff, all the passwords are safely locked away where the Dean can get at them, if needed. We make sure that even if we are all gone, whoever comes after can get access.
These days the university has policies to that effect but we did it before then because that is what you do. You have a disaster plan, and that plan includes what happens if you aren't around.