At around 10:30 a.m., a gas leak occurred on a valve of a residential propane tank. The system consisted of two 3.2 tonne interconnected storage tanks supplying a residential building and connected to one another. A cordon was set up. Twenty-four units were evacuated at a council estate. The gas was cut off, affecting 60 people.

The leaking tank was emptied, the safety valve was replaced, and a plug was placed on the gas supply to isolate the tank. Then, both tanks were disconnected from one another. The gas supply valve on the second (working) tank was opened and gas was restored to residents at 5:15 p.m.

An analysis of the causes conducted by the propane distributor showed that the driver who delivered the propane on 25 January (two days before the event) had filled the tank above its maximum. Both tanks were fitted with mechanical gauge and a high-point gauge to measure the amount of gas inside them. The mechanical gauge was faulty, and the delivery driver should have realised this by comparing it with the high-point gauge.

This oversight resulted in the mechanical gauge’s failure not being detected and the tank being filled above its maximum of 85%. Two days later, a change in the outdoor temperature caused the liquid propane to thermally expand and the pressure inside the tank to rise. This increase in pressure caused the safety valve to open.