Hold the lettuce … and the needles? Delta Airlines and the FBI are trying to determine how needles found their way into four turkey sandwiches that were served on separate flights from Amsterdam to the United States, the airline said Monday. The objects, which appeared to be sewing needles, were discovered on planes headed to Minneapolis and Seattle, and on two flights to Atlanta. Two of the needles were found by passengers. The airline quickly ordered all of its flights from Amsterdam to stop serving the sandwiches and offer sealed prepackaged foods instead. “This is a terribly upsetting situation,” said a spokesperson for Gate Gourmet, the Netherlands-based company that provided the sandwiches to Delta.