Italian firefighters rescued 25 people trapped on the French side of a high mountain pass by severe flooding that killed two people in Italy, while 15 people were stuck in a train station for the night and eight more remained missing on Saturday in France. A storm that overnight moved across south-eastern France into north-western Italy caused major flooding on both sides of the border, destroying bridges, blocking roads and isolating communities. In Italy, a firefighter was killed during a rescue operation in the mountainous northern region of Val d’Aosta. A search team found a body in the Piedmont region's Vercelli province, where a man was swept away by flood waters late on Friday. Italian firefighters used a helicopter to move 17 people to safety from the French town of Vievola, including a woman with two grandchildren. A bulldozer fetched another eight people who managed to climb the Col de Tende, a high mountain pass linking France and Italy, to a tunnel. Fifteen more people took shelter in the Vievola train station after the operation to rescue them was put off until daylight. The spokesman for Italy’s firefighters, Luca Cari, said a search was ongoing for a missing shepherd who was pulled into flood waters on Col de Tende. His brother managed to grab on to a tree and was saved and authorities are searching on the French side for the shepherd. The situation at the tunnel on the high mountain pass was complicated by the fact French emergency responders cannot access their side because of flood damage, Mr Cari said. Unrelenting rainfall overnight hit levels not recorded since 1958 in northern Italy's Piedmont region, where as much as 630 millimetres of rain fell in 24 hours, according to the Italian civil protection agency. Hundreds of rescue operations were carried out. Eleven campers were saved in Vercelli province, where floodwaters hit 20-year highs. Alpine rescue squads helped seven people find safety after their houses cut off by flooding at Terme di Valdieri. Some had to be carried on stretchers owing to the muddy conditions and accumulation of detritus. In south-eastern France, almost a year's average rain fell in less than 12 hours in the mountainous area surrounding the city of Nice. Nice mayor Christian Estrosi said more than 100 homes were destroyed or severely damaged in the area. French Prime Minister Jean Castex, who flew over the area in an helicopter, confirmed that at least eight people were missing in France, including two firefighters whose vehicle was carried away by water when a road collapsed. “I cannot hide our grave concern on the definitive toll,” Mr Castex said. Many worried families had not heard from their relatives because phone services were cut off in the area. “As I speak, priority goes to searching for victims, providing supplies and accommodation for the people affected, and restoring communications," Mr Caztex said. Rescue efforts included 871 personnel and military helicopters and troops helped with emergency assistance, Mr Castex said. On Saturday, French President Emmanuel Macron expressed gratitude towards rescuers on Twitter. "Together we will get through this," he said. France’s national weather agency, Meteo France, said that up to 500 millimetres of rain were recorded in some areas, the equivalent of almost one year of average rainfall. The agency issued a danger alert on Friday and all schools in the region were closed. Local authorities urged people to stay at home. In central Switzerland, flooding along the Reuss river caused the closure of a stretch of the A2 motorway, a major trans-Alpine route. Further east, 13 residents were rescued from their homes in the town of Diesbach because of flooding.