laboratory on air canada flight 797. the plane landed but 23 people on board died. after that smoke detectors and automatic fire extinguishers were mandated in aircraft lavatories. in 1996 hazardous cargo on a flight caught fire. the plane crashed in the florida everglades. 110 people died. it led to new cargo hold safety rules. but not finding flight 370 or its data recorders could be a missed opportunity for change. >> whatever brought down that flight, whether it was fire, hijacked, pilot suicide, explosive decompression, a bomb, whatever, it's important to find that out so we can fix it so it doesn't happen again. >> and it's security too. the september 11th hijackings led to strengthened cockpit