Storing large amounts of gas containers at one place has always been a major threat. Various factors can potentially trigger an explosion which could damage elements within a substantial radius. In this article a numerical analysis of a gas cylinder subjected to an external explosion is presented. The simulation was modelled in the ANSYS LS-DYNA software using the MM-ALE method, which allows a full visual presentation of the shock wave propagation and its interaction with the gas cylinder. Calculations are carried out 3 times for the same cylinder with 3 different wall thicknesses: 6 mm, 3 mm and 1 mm. Performed calculations showed an inverse relationship between the wall thickness and the deformation measured by nodal displacement. Moreover, the gas cylinder with a 1 mm thick wall didn’t withstand the stress caused by the explosion. The blast wave was created by detonating 470 g of trinitrotoluene, placed 70 mm away from the gas cylinder.