The starboard engine of a United Airlines passenger jet burst into flames over Denver on Saturday — forcing an emergency landing and causing a huge piece of engine casing to land on a suburban front yard, officials and witnesses said. Amazingly, no injuries were reported from on board Honolulu-bound United Flight 328 or on the ground — despite dramatic images showing the rattling, burning engine and the front yard wreckage. The Boeing 777 took off from Denver International Airport at 12:49 p.m. with 231 passengers and 10 crew members on board but quickly experienced engine trouble and returned to Denver...