A friend tells me that Charles Kidd at Debrett has confirmed to him the death of the 10th Viscount POWERSCOURT on 25 July 2015 in Thailand. He's succ by his only son from his 1st m:
Mervyn Anthony WINGFIELD (b 21 Aug 1963) succ his father as 11th Viscount POWERSCOURT 2015 but has yet to establish his claim and appear on the The Roll of the Peerage (his father did not appear on The Roll). He m 2010 Sarah Ann d of Victor HALL of Lower Swell, Gloucestershire. No issue
UNCLE LIVING
Hon Guy Claude Patrick WINGFIELD (b 1940) unm. Heir presumptive
The line of succession then passes to the present Viscount's cousins, over 30 by my count.