On 20 October 2013, a Boeing 757-200 Co-Pilot believed his aircraft was at risk of stalling when he saw a sudden low airspeed indication on his display during a night descent and reacted by increasing thrust and making abrupt pitch-down inputs. Other airspeed indications remained unaffected. The Captain took control and recovery to normal flight followed. The excursion involved a significant Vmo exceedance, damage to and consequent failure of one of the hydraulic systems and passengers and cabin crew injuries. The false airspeed reading was attributed by the Investigation to transient Ice Crystal Icing affecting one of the pitot probes.