Fire officials say one person is unaccounted for and 11 people have been left homeless by a two-alarm fire at a two-family home in Springfield.  The blaze at the Euclid Avenue home in the city's Forest Park neighborhood was reported just after 1 a.m. Wednesday.  Firefighters were hampered by below-freezing temperatures and icy conditions that seized up equipment and made the sidewalk slippery.  Springfield Fire Department spokesman Dennis Leger  says the home appears to be a total loss and the Red Cross is helping the displaced residents.  The unaccounted for person lived on the first floor and investigators are trying to determine whether he was home at the time.