NORWALK - The aftermath of Wednesday's winter blast left many sidewalks and parking lots dangerous for residents in southwestern Connecticut Thursday.Some parents of students at the Jefferson Science Magnet School in Norwalk were upset by the conditions at the school Thursday morning. Several parents said the sidewalk conditions were too dangerous and that there was no choice but to walk on the snow.Crews assisted the school with sanding the area, but some of the parents said more shoveling and sanding was needed. Others suggested that the school should have had a delay Thursday morning.The spokeswoman for the Norwalk School District said it is the responsibility of the Parks and Recreation Department to take care of the school's sidewalks.A director for the department said there are 18 people that must get to 22 locations between 7 a.m. and 8 a.m. on mornings like Thursday. He said it is impossible to get to that many locations with the current size of his staff.