Clyde Tombaugh’s plans to go up to Lawrence to college were foiled by an inopportune hailstorm — the oats that were to furnish his college funding were destroyed.  Crop prices in 1928 were solid and would have provided a substantial income to the Tombaughs.  But disaster proved an opportunity.  The chance hailstorm that destroyed the oats caused Clyde to write to V.M. Slipher at Lowell Observatory for advice; as a result, Slipher invited Clyde to come to Flagstaff for a trial period of employment, which put Clyde in a position to find Planet X — something he may actually have been uniquely qualified to do.  As an outsider at Lowell, he was especially eager to please.  In need of work, he was unlikely to complain.  He had little sense of the quixotic nature of the project, at least at first.  And, as luck would have it, he was just the sort of exceptionally methodical worker the Planet X search required. 

But without the hailstorm, none of it would have happened.