Accident investigators have determined that Tunisian mechanics replaced a faulty fuel gauge in the ATR 72 that crashed off the northeast coast of Sicily on August 6 with the wrong model, a mistake that apparently led the doomed airplane’s pilots to upload less fuel than they needed to complete their trip from Bari, Italy, to Djerba, Tunisia. As a result, the airplane ran out of fuel one hour into the flight, forcing the pilots to ditch into the Tyrrhenian Sea, where 16 of the 39 occupants perished. According to a report issued by Italy’s national agency for air transport safety (ANSV), the day before the crash the mechanics installed a fuel gauge designed for the 48-seat ATR 42 in the larger ATR 72, which carries more fuel. When the airplane lost power, the gauge still read 1,984 pounds of fuel in each wing tank. Based on the ANSV report, Italy’s civil aviation authority, ENAC, has banned Tunisair regional subsidiary Tuninter from operating in Italy.