[mkl]

https://en.wikipedia.org/wiki/Hyatt_Regency_walkway_collapse

Longitudinal forces on the bolts there, not shear. A change during construction doubled the force on the nuts and the bolts went through weak weld joints in beams. (Also not a PE.)

[I_Am_Nous]

>A surgeon spent 20 minutes amputating one victim's pinned and unsalvageable leg with a chainsaw; that victim later died.

Wow

[mkl]

Yeah, the page is a pretty harrowing read.