A rusty casket washed up in an arroyo near Aztec Speedway during the recent flooding. The casket’s appearance mystified Aztec Well Servicing employees, who spotted it on Wednesday. An employee opened it and saw what he thought were bones underneath torn bedding inside, said Jason Sandel, the company’s executive vice president. Employees called police, and Aztec Police Chief Mike Heal and Sgt. Joseph Gonzalez responded. But they didn’t find bones or body parts.