A Friendly Favour Turned Fatal: The Horse Bungee Pool Tragedy

A surprising new addition of the Western Australian Work Health and Safety (General) & (Mines) Regulations 2022 were, for the first time in legislation dealing with safety in Western Australia - the words Geotechnical Engineer. In Regulation 306 - Additional controls: trenches, when a PCBU excavates a trench of at least 1.5 metres deep, they must ensure that all sides of the trench are adequately supported by shoring, benching or battering if there is a risk to Workers arising from the collapse of the trench. Adequate support is not required if written advice from a Geotechnical Engineer is received stating that all sides of the trench are safe from collapse without support. This written advice may consider specific natural occurrences affecting the risk of trench collapse and must state the period of time to which the advice applies. Our mere acknowledgement might make you feel hopeful and positive that things have moved in the right direction. Yes and no. Like the saying goes - these Regulations are written in blood, and this article details how a perceived simple and benign favour between friends turned into a fatality.

In Inspector Christensen v Wadwell Group Pty Ltd (ACN 125 970 345) as trustee for the Wadwell Family Trust [2012] NSWIRComm 126, a seemingly innocuous "favour" between friends to build a horse bungee pool resulted in a tragic trench collapse, costing one life and injuring others. This case serves as a stark reminder that even informal projects demand rigorous safety precautions and professional expertise.

Two friends, not engineers or builders, designed the pool, which involved a 17 metre long, 2.4 metre wide trench, varying from 2.3 to 3.5 metres deep. Soil was piled dangerously close to the edges, and a backhoe was parked nearby overnight. The unsupported trench walls stood for over 24 hours before concrete panels were to be installed.

During the panel installation with three people inside the trench; a trench wall collapsed. One person was killed, another trapped, and a third narrowly escaped. The subsequent investigation revealed a litany of safety failures: no principal contractor, no WHS management plan, no inductions or safe work method statements (SWMS), inadequate risk assessment, and a complete absence of shoring.

The Directors involved, from a residential plastering company, claimed ignorance of excavation risks. However, the judge found their corporation culpable for failing to ensure the safety of personnel working in and near the excavation. The corporation was fined $200,000, and the Directors received individual fines. This tragic event underscores the absolute necessity of geotechnical assessments and stringent safety measures in all excavation work, regardless of project scale or informal arrangements.