A blocked pitot tube fed false airspeed to a Boeing 757 autopilot, the crew never recovered from the stall that followed, and all 189 aboard Birgenair Flight 301 died
All 189 aboard Birgenair 301 died in 1996 when a blocked pitot tube fed the 757's autopilot a false rising airspeed and it pitched the nose steadily upward off Puerto Plata; the crew, confused by conflicting warnings, pulled thrust, raised the nose further and did not respond to the stall warning.