By Scott Robertson Leaving many observers surprised at how quickly the action was taken, Bristol, Va.-based Alpha Natural Resources voluntarily filed for Chapter 11 bankruptcy protection Aug. 3. As late as four months ago, the coal mining company had reported having $476 million in cash. Immediately after filing, Alpha began assuring customers and vendors it plans to continue to conduct "business as usual" as the restructuring unfolds over the course of the next year to year-and-a-half. A statement to those companies which Alpha published online said, "We expect to continue operating, paying employees, suppliers and vendors, and delivering high-quality service to our customers. We're committed to maintaining safe, compliant and productive operations." Alpha was scheduled to repay a convertible bond at the beginning of August, but chose to file for Chapter 11 protection instead.