Can PID kill you?

Yes, but... ..This is thankfully very rare. Women admitted as an emergency with an iud-associated pelvic abscess, which is the worst form of pid, are at risk of dying, and generally require a huge amount of cardiovascular support from the anesthesiologist while the definitive surgery is performed.
Extremely unlikely. Theoretically PID could be fatal, in event of an unusually severe case with abscess and complications from that. But extremely unlikely, especially if the infected person follows her doctors' advice about treatment, follow-up, etc.