Danny operates a plumbing business, and this year the three-year-old van he used in the business was destroyed in a traffic accident. The van was originally purchased for $20,000 and the adjusted basis was $5,800 at the time of the accident. Although the van was worth $6,000 at the time of accident, insurance only paid Danny $1,200 for the loss. What is the amount of Danny's casualty loss deduction?