One of my coworkers did this. The bag ignited and was burning in the microwave. Smoke poured out and the whole office stunk. I can't believe the alarms did not go off. We opened all the windows, set up fans etc. but the smell would not go away. We inhaled so much smoke I felt like I smoked a pack of cigarettes. I feel for you, we wanted to banish this woman from the office! She kept walking around all day sheepishly saying, "I'm sooooorrrrrryy." 
