Heavy machinery comes with hazards.
Flying is fun and satisfying, but also has hazards. I've lost quite a few friends and colleagues in flying accidents. People make mistakes (even a trivial one can kill), get confused, disoriented, distracted, or misled, and things sometimes break.
Farmers and railway crews are two civilian occupations that are hazardous because of heavy machinery. Derailments (track breakages, vehicle strikes, washouts, rockslides, crushes between railcars during coupling/uncoupling operations (the latter happened to an engineer friend of mine) are not uncommon on railways, and tractors can overturn and crush farmers, who also occasionally succumb to silo gas or get limbs caught in other farm machinery.
Stuffed into a manoeuvering metal box, surrounded by large quantities of fuel, hot hydraulic fluid, and explosives, with limited vision, rough terrain, and confusing/rapidly changing tactical situation - what could possibly go wrong? With slight word changes, that also applies to ships and aircraft.