This is dreadful and my heart goes out to his family.
As Whisky Delta says ramp workers do get complacient working aroud aircraft. Last year I had somebody walk behind a 767 and get blown over. He was O.K. but admitted he just forgot the hazard in a momentry laps in concentration. It was lucky he didn’t walk in front of the engine.
BTW the danger zone around the air intake on a 737-3/4/500 extends out about 7 feet at ground idle. To get to the engine to perform leak checks you either have to go outbord of it (the safest way and the only way I do it!). Or walk in with your shoulder touching the fuselage untill you are behind the engine. At anything above idle that area is inside the danger area.
If you want to see the safest area to be in when the engines, look out for the engineers, They are usually in their vans asleep!!!

Rgds Cking