Four buildings were destroyed by fire in downtown Waterloo early thismorning. Fire Chief Frank Magsaman says the buildings were all joined by aventilation system, which allowed the flames to quickly spread. He says thefirst fire trucks arrived around 2 a-m.Chief Magsaman says the firefighting efforts were hampered by heavythunderstorms.Today marks the beginning of a citywide celebration called “My WaterlooDays” which includes a parade tonight. Officials say they’ll likely movesome events away from the popular downtown area due to the fire damage.One firefighter was blown through a window in an explosion but he was notseriously hurt.