sentences:  While the operation was going on, General Salan tasked Colonel Jean Gilles with establishing an entrenched fire support base at Nà Sản to stop Giáp's offensive.Nà Sản, located on Route Provinciale 41 (RP 41), was a valley of 2 km × 1 km surrounded by 24 hills that could serve as natural defense positions.In early October 1952, there was a single outpost and a short airstrip, both guarded by a company under the command of a non-commissioned officer.