The Pike River mine (PRM), an underground coal mine in New Zealand (NZ), exploded in 2010. This paper analyses the causes of the disaster, with a particular focus on the systems engineering and organisational contributions. Poor systems-engineering contributed via poorly designed ventilation, use of power-electronics underground, and placement of the main ventilation fan underground. Management rushed prematurely into production even though the technology development in the mine was incomplete. Investment in non-productive infrastructure was deprioritised resulting in inadequate ventilation, and the lack of a viable second emergency egress. The risk assessments were deficient, incomplete, or not actioned. Warnings and feedback from staff were ignored. Risk arises as a consequence of the complex interactions between the components of the sociotechnical system. Organisations will need to strengthen the integrity of their risk management processes at engineering, management, and board levels. The systems engineering perspective shows the interacting causality between the engineering challenges (ventilation, mining method, electrical power), project deliverables, management priorities, organisational culture, and workers' behaviour. Use of the barrier method provides a new way to examine the risk-management strategies of the mine. The breakdowns in organisational safety management systems are explicitly identified.