An investigation is underway into what caused a Tunisian passenger plane to crash near Sicily killing at least 13 people including two children. The Tunisair charter flight, carrying 34 Italians and five crew, ditched into the sea off the Mediterranean island after reporting a “lack of engine power” yesterday afternoon. With at three people missing, the search and rescue operation continued well into the night. The plane was heading from Bari to the popular Tunisian resort island of Djerba when the pilot made a distress call to Palermo requesting an emergency landing. The crash is Italy’s worst air accident since 2001 when 118 people were killed in Milan when a private jet collided with an SAS airliner.