Several workers from various companies were working on the construction of an industrial unit intended to house data services for a bank. On 5 November 2008 as Adam Johnston walked through a storeroom with a colleague, one of 80 argonite gas cylinders discharged, causing a chain reaction which resulted in 65 of the other cylinders being discharged. The cylinders, which each weighed 142kg, flew across the room at up to 170 miles per hour. One of the cylinders struck and killed Mr Johnston and other colleagues were forced to dive for cover. Some of the cylinders had travelled with such force that they penetrated walls and ceilings. In addition to Mr Johnston’s death, six employees were injured and there was a significant amount of damage to the property.

An investigation by the HSE found that the works had not been properly managed or coordinated between the companies on site, which had failed to carry out an adequate risk assessment for the works. It was noted that employees of other companies were able to enter the argonite store without knowing the risks involved or having those risks explained to them, and that those risks were not properly controlled. It was also noted that it was only by chance that there had been no further fatalities in the incident.

The principal contractor, Crown House Technologies, pleaded guilty to breaches of s2(1) and 3(1) HSWA and was fined £117k with costs of £119,394. Kidde Fire Protection Services, which had been sub contracted to supply and install fire protection equipment, pleaded guilty to breaches of Regulation 6 and Regulation 13(2) Construction (Design and Management) Regulations 2007 which relate to failures to coordinate, plan and manage their work, and were fined £165k with £59,697 in costs. Kidde Products Ltd, which carried out the installation work, pleaded guilty to breaches of s2(1) and 3(1) HSWA and were fined £165k with £59,697 in costs.