In my last position, I was so burnt out, from 3am emails, no time off, the lack of support from my supervisor, the constant stream of new projects, but what sealed the deal, the last nail in the coffin was a dead weight employee gave notice. I was polite and said, thank you, then proceeded to have a meeting with my boss, and said let's celebrate. However, instead of celebrating, we needed to have meetings with HR over the next 2 weeks about what went wrong and how we could have salvaged this employee.
I gave notice before dead weights last day.