I had to take my aunt off life support. She went into the hospital one week with pneumonia and was released. She went back into the hospital again the following week and was diagnosed with lung cancer. Due to her state she was not a candidate for treatment.
Being her POA (I didn't know I was until my mom called me) I was the one who had to make the decision to take her off life support. Watching the monitors and listening to the start beeping. So difficult, and then her older sister (my mom) would come and go out of the room until she passed. The nurse told me it took take a few minutes or it could be hours. Luckily, it wasn't very long.