On 16 December 1929 about 5,000 miners demonstrated Protest against the introduction of non-union labour into the Rothbury mine by the conservative Bavin government , which had taken over Change_of_leadership the colliery .

The government called in Come_together 70 New South Wales police officers from districts outside Newcastle to protect Defending the colliery and allow Preventing_or_letting the entry of non-union labour .

The FAA replaced the strikers with non-union workers .

although the owner of the mine originally agreed Agree_or_refuse_to_act with the union to observe Perception_active the strike Attack , when the price of coal went Self_motion up , he hired Employment non-union workers to produce Creating and ship Bringing out coal , as he had high debt in start-up costs Cost .

A twentieth victim from the non-union group was later murdered Killing , bringing Bringing the death Death total to 23 .