We were flying in biz from YYZ to BGI about a month after 9/11 with our one year old daughter and our nanny. About an hour into the flight our daughter explodes with a massive and extremely smelly poop that overflows her diaper. My wife and our nanny rush her into the front lav and spend 20 minutes cleaning her up (with the door open and blocking the door to the cockpit) while I clean up the seat and my clothes (luckily I had a change in my carry-on). Everyone is mad at us - the rest of the biz cabin can't breathe or use the lav and the FAs are in a panic (at least partly because it's a potential security risk and everyone is paranoid). We spent the whole flight apologizing to people - I was never so glad to get off a flight as I was to get off that one!!