Ok, the ten second analysis:
We have a groundskeeper who was apprently assigned to trim weeds around the BoulderDash site.
Said groundskeeper was wearing sound protection against the sound of the weed trimmer, which probably did impair his hearing significantly.
Said groundskeeper was struck by roller coaster.
That's whats known.
As Gemini stated above, at the very least standard lock-out procedures should have been in place. Lock out is an inudstry standard means of protection against mechanical equipment.
Since the ride operated, obviously either
a) The groundkeeper did not lock out
b) Somone tampered with the groundskeepers lockout, either with a duplciate key, lockcutter, or the lock wasn't properly secured in the first place.
I cannot fathom any one tampering with another employee's lockout, so we'll assume he did not lock out. Whether that was an option available to him is unknown at this time.
Now let's put ourselves in the mindset of the young worker. "That ride never starts testing till 9, I'll only be here till 8:45, so I'll save myself 5 minutes and a walk to the mechanical room/control console and jump in here, trim the weeds and be out"
Unfortunately, the ride started testing early, but even if it did let's consider.
According to the newspaper article he was in fact underneath the tracks, in a vulnerable position, probably a position that he just couldn't step back from, the article also stated that he couldn't hear becuase of the ear portection for the weed trimmer, and was facing away from the train.
Which means, OSHA is gonna have a FIELD DAY with this one. Especially if the inference in the article is correct that there apparently was no lock out, and they relied on the rather ancient system of walking the ride and visually insecpting the site before startup. You can seea lot but you might miss a moving person who just may happen to always escape your glance. Especially if just like the groundskeepr, "No one is ever there, so I'll just run down and have a Coke and a smoke, then come back and start the ride"
There is also that mindset: "They won't send a train on me, SOMEONE else will look out for me, this can't really be happening"
Just from waht I know or am doing armchair investigating on (hey Harry Caulder didn't take a look at the Rocket or its demolished train either), I feel that this is a shamless tragedy that could have been easily prevented. No one should have to put their life on the line to go to work. Many prayers for the workers family and friends.