Two incidences of DEF contamination took place in November 2017, in Omaha, Nebraska, and in August 2018, in Opa Locka, Florida. The most recent contamination event occurred on May 9 at the Punta Gorda, Florida, airport, when DEF was mistakenly added to fuel in a fuel truck. Two Citation 550s operated by charter company Air Trek were serviced with the contaminated fuel. One, enroute from Naples to Niagara Falls, New York, suffered an engine flameout, followed by a second engine failure, and diverted successfully to Savannah, Georgia. The second, enroute to Chicago, had a single engine failure, and landed safely in Louisville, Kentucky.