Severe weather has damaged more than 50 homes in several Florida towns, officials said, and schools in the Florida Keys were canceled Wednesday because of heavy rain and frequent lightning. No serious injuries were reported. Damage assessments were under way in Plantation and Sunrise, Florida, after a suspected tornado swept through south Florida about 10 p.m. Tuesday. At the time, a tornado warning for the area was expiring, said Joel Gordon, battalion chief for the Plantation Fire Department.