Due to flooding in canton Valais, southern Switzerland, the A9 motorway between Sierre and Sion is closed. The entire canton is on alert, cantonal authorities said on Sunday. Flooding and debris flows occurred along the Rhone River and its tributaries following heavy thunderstorms on Saturday and during the night. Added to this was the melting snow and the fact that the ground was already saturated with water. Do you want to read our weekly top stories? Subscribe here. The A9 motorway was closed between Sierre and Sion on Sunday morning. Numerous other roads in the canton were also impassable, including the Simplon axis. Traffic was also severely disrupted on the Simplon railway line. The situation on the roads and railways could change quickly, wrote the cantonal command centre. It recommended checking online before travelling. Hundreds of relief workers were deployed in Valais, namely 20 command units, around 320 firefighters from over 30 corps, 100 members of the civil defence ...