It is possible that the construction worker which fell off a 100-foot ladder didn’t die because he was on the 1st step or the lowest step of the 100-foot ladder. This is a riddle and from the riddle itself, there isn’t any indication that the construction worker was at the 100th step. Therefore, he may be at the 1st step and thus, when he fell, he didn’t die since he was at the lowest step.