World Trade Center build at halfway point
Steel construction has reached the halfway point for New York's 1 World Trade Center.
The Manhattan building, also known as the Freedom Tower, stands more than 600ft (180m) high.
The tower will eventually have 104 stories, with an antenna reaching hundreds of feet higher, bringing it to 1,776ft - making it the tallest in the country.
Steve Coleman, spokesman for the Port Authority of New York and New Jersey, said he was hopeful they would finish the building by the end of 2011.