This episode looks at the tragic death of 12-year-old D.H. during a scuba training dive and explains it not as one person’s mistake, but as a failure of the whole system around her. Using court documents and a safety science approach, the analysis shows how many “normal” things came together — rushed training, poor visibility, tired staff, missing safety equipment, weak rules, money pressure, and lack of oversight — to create a situation where there was no real safety margin left. The key message is that this was not a random accident or a single bad decision, but the result of a system that allowed risky practices to become normal. The goal is not blame, but learning: understanding how everyday routines, shortcuts, and pressures can slowly increase danger, and how changing the system — not just individuals — is the only real way to prevent this from happening again.

Original blog: https://www.thehumandiver.com/post/learning-from-tragedy-dh

Links: Court filings: https://www.documentcloud.org/documents/26789283-dylanharrisonlawsuit/

Purpose of investigation blog: https://www.thehumandiver.com/post/what-is-the-purpose-of-an-investigation

Learning from Emergent Outcomes and LEODSI: https://www.thehumandiver.com/lfeo

Psychological safety: https://lup.lub.lu.se/student-papers/search/publication/9151225

Research around “stop work” orders: https://www.researchgate.net/publication/352017590_Deciding_to_stop_work_or_deciding_how_work_is_done

https://www.sciencedirect.com/science/article/abs/pii/S0925753517308871

RSTC guidance and Standards: https://www.youtube.com/watch?v=kNRrrosDJYs

Trade off between performance, cost and resources: https://youtu.be/vtgIwHrUWVQ?list=PLNXuyLsCTX6hHS3newpcROfJ_JiI27q3C&t=555

Regulated environments such as military aviation: https://www.mdpi.com/2313-576X/8/2/37

Barriers to learning from adverse events: https://lup.lub.lu.se/student-papers/search/publication/9151225

Social acceptance of drift: https://www.thehumandiver.com/post/normalisation-of-deviance-not-about-rule-breaking