Task: Question Answering
Input (English): Passage: Half of Minneapolis–Saint Paul residents work in the city where they live. Most residents drive cars, but 60% of the 160,000 people working downtown commute by means other than a single person per auto. The Metropolitan Council's Metro Transit, which operates the light rail system and most of the city's buses, provides free travel vouchers through the Guaranteed Ride Home program to allay fears that commuters might otherwise be occasionally stranded if, for example, they work late hours.On January 1, 2011, the city's limit of 343 taxis was lifted.Minneapolis currently has two light rail lines and one commuter rail line. The METRO Blue Line LRT (formerly the Hiawatha Line) serves 34,000 riders daily and connects the Minneapolis–Saint Paul International Airport and Mall of America in Bloomington to downtown. Most of the line runs at surface level, although parts of the line run on elevated tracks (including the Franklin Avenue and Lake Street/Midtown stations) and approximately 2 miles (3.2 km) of the line runs underground, including the Lindbergh terminal subway station at the airport. 
Question: What is the original name of the line that has approximately 2 miles of it underground?
Output (English): Hiawatha Line.