As heavy torrential rains batter Uttarakhand, a bridge over the Song River in Dehradun has been closed for traffic amid an alarming rise in the water level on Monday. Earlier, the Dehradun Defence College building in Maldevta district collapsed due to incessant rainfall and floods, and the rising water level of the Nandakini River crossed the danger mark in the Nandagar area of the Chamoli district on Sunday night.