On 19 September 2024, a Boeing 757-200 making its initial descent to San Francisco was approaching its interim cleared level of FL 310 with the seat belt signs on prior to beginning descent from FL380 when a TCAS ‘CLIMB’ RA was annunciated. The type-inexperienced first officer’s response manoeuvre was abrupt enough to cause serious injury to two unsecured passengers and minor injuries to two unsecured cabin crew. Flight data showed that a 3° pitch up had been made within one second resulting in a vertical load factor of over 2g.