Esther owns a large home on the East Coast. Her home is surrounded by large, mature oak trees that significantly increase the value of her home. In August 2016, a hurricane damaged many of the trees surrounding her home. In September 2016, Esther engaged a local arborist to evaluate and treat the trees, but five of the largest trees were seriously weakened by the storm. These trees died from disease in 2017. Esther has ascertained that the amount of the casualty loss from the death of the five trees is $25,000; however, she is uncertain in which year to deduct this loss. Discuss whether the casualty loss should be deducted in the calculation of Esther's 2016 or 2017 taxable income?