Colorado Springs (UP) In the past two months, four men have died accidentally. No signs of suspicious circumstances have been found in any of the cases.

Investigators question how, though, four severely disabled men could manage to get to the areas where they died and how they were able to maneuver well enough to become involved with the machinery that eventually killed them.

Two months ago, Thomas Shook was found tangled in the conveyor belt at the factory he once owned. Three weeks later, a family member discovered Jackson Mason under a tractor on his farm, a tractor the man had been unable to operate for over six years.

The first of this month, Graham Tyler went over a steep drop - on a three-wheel off road vehicle. Tyler's right leg was amputated over a year ago.  Last week, Russell Brosh fell into a running concrete mixer on one of his construction company's locations. With one useless arm, no one understands how he started the machine.

Four men, all disabled, died in the space of two months. No witnesses have been found for any of the accidents.