Niena's business incurred a casualty loss in 2010. Immediately before the casualty, her business truck had an adjusted basis of $10,000 and a fair market value of $20,000. Immediately after the casualty, the truck had a fair market value of $11,000. Because of the truck damage, Niena's insurance company provided $4,000 as a reimbursement in 2010. What was Niena's 2010 casualty loss deduction?