Before 1944, the Allies bombed targets in France that were part of the German war industry. This included raids such as those on the Renault factory in Boulogne-Billancourt in March 1942 or the port facilities of Nantes in September 1943 (which killed 1,500 civilians). In preparation of Allied landings in Normandy and those in the south of France, French infrastructure (mainly rail transport) was intensively targeted by RAF and USAAF in May and June 1944. Despite intelligence provided by the French Resistance, many residential areas were hit in error or lack of accuracy. This included cities like Marseille (2,000 dead), Lyon (1,000 dead), Saint-Étienne, Rouen, Orléans, Grenoble, Nice, Paris and surrounds (1000+ dead), and so on. The Free French Air Force, operational since 1941, used to opt for the more risky skimming tactic when operating in national territory, to avoid civilian casualties. On 5 January 1945, British bombers struck the "Atlantic pocket" of Royan and destroyed 85% of this city. A later raid, using napalm was carried out before it was freed from Nazi occupation in April. Of the 3,000 civilians left in the city, 442 died.