people often toss their money into commodoties (gold, oil, farm products etc) when events may devalue other investments that depend on unstable economic variables.
in otherwords, if this crash makes a company go broke, their shares are worth nothing whereas oil, gold etc will always be worth some value regardless.
this may play with the oil price a bit but most of it is panic exploiting gouging at the owner-operator level. someone with a better knowledge of economics may be able to explain it better.