Marin operates a manufacturing business, and this year the three-year-old van she used in the business was destroyed in a fire. The van was originally purchased for $21,600 and the adjusted basis was $5,600 at the time of the accident. Although the van was worth $6,160 at the time of accident, insurance only paid Marin $1,400 for the loss. What is the amount of Marin's casualty loss deduction?