Failure Files

On April 22, 2021, one undertorqued connecting rod bolt destroyed a Washington State Ferry's diesel engine, started a fire, and caused $3.8 million in damage. The NTSB's confirmed finding is a masterclass in why torque specifications aren't suggestions.

On January 5, 2024, a Boeing 737 MAX 9 door plug blew out mid-flight because four retention bolts were never reinstalled after a factory rework procedure. The NTSB published its final report in June 2025. Here is what every maintenance professional and fleet manager should take away from this incident.

An NTSB investigation confirmed that a single undertorqued connecting rod bolt caused a catastrophic engine failure and fire aboard the Washington State Ferry Wenatchee in 2021, resulting in $3.8 million in damage. Here is what went wrong, and why torque is a fastener specification — not an afterthought.

In 2013, 32 anchor bolts on the newly opened San Francisco-Oakland Bay Bridge snapped — despite meeting every spec they were given. Here's what hydrogen embrittlement, sustained load, and saltwater exposure taught the engineering world about fastener selection and the environment.

On July 17, 1981, two elevated walkways collapsed at the Hyatt Regency Hotel in Kansas City, killing 114 people. The cause traces back to a single design change involving threaded rods — and a load that nobody recalculated. Here's what it still teaches us about fastener selection today.