As a Virgin Atlantic flight taxied up to Terminal 3 at McCarran Airport, the pilot came over the loudspeaker to make an announcement. “He said not to worry about the fire engines,” said Daniel Roberts, who was flying into Las Vegas from London. The water fountain arch created by the pair of fire trucks on the tarmac was the first of many surprises for passengers aboard the flight, which was the first to arrive at the brand-new, $2.4 billion Terminal 3, which officially opened Wednesday.