Dec 29th. British Airways to London Heathrow. Flight was called approx. 60 mins before departure. Door at the foot of the escalator was opened escalator switched on door at the top of the escalator was not opened. Passengers coming up the escalator had nowhere to go and were being piled on top of each other. Emergency stop button in an awkward place so it took ages to stop it as more people were being thrown onto each other. Lots of people screaming. No one from Pisa airport took any notice. After passport control it was the usual boarding chaos one would attribute to Ryanair. Will try Genova next time.