DETROIT (Reuters) - Northwest Airlines apologized on Wednesday to 40 American Muslims who were barred from a recent flight to Detroit, but denied it discriminated against the group, which was returning from a Hajj pilgrimage. Northwest said the pilgrims failed to check in one hour before their transatlantic flight from Frankfurt, Germany, to Detroit was scheduled to depart, as is required. The passengers arrived in Frankfurt via a charter flight from Mecca, Saudi Arabia, and mistakenly believed they were cleared to board the Northwest flight, but were not. "The passengers were accommodated on the next available flights to Detroit," Northwest...