Natural gas continues to be one of the basic energy sources used as fuel in the power sector, in industries and in households. The potential and attractiveness of this fuel is gaining special significance in the current energy transitions from coal-based power engineering to power generation based on renewable energy sources. Natural gas is supplied to consumers mainly through a network of pipelines, which ensures a relatively high reliability of the supply. Still, failures occur due to the corrosion of pipeline walls, material defects or human errors, which can result in uncontrolled release of gas. The released gas can trigger dangerous phenomena, such as fires and explosions. This paper presents an analysis of the causes and effects of damage to a medium-pressure pipeline caused by earthworks carried out within an area where a pipeline is located. Holes in the pipeline due to the impact of an excavator bucket are analysed. The impact of the excavator bucket may cause a rupture equal to 50% of the pipeline’s cross-sectional area. Hazard zones related to fires and explosions due to the released natural gas are presented. For the analysed pipeline with a diameter of 0.5 m and a gas pressure of 5 MPa, the range of hazard zones arising due to pipeline damage caused by an excavator bucket can reach about 200 m.