56 Halifaxes from 419, 427, 428, 429, and 434 Squadrons were ordered to attack the rail yards in Modane. The crews were over the target at between 14,000 and 19,000 feet, releasing 7,000 lbs of incendiaries and 215,000 lbs of high explosives. According to reports, this target was in a steep valley and the marking was not accurate so bombing was scattered. Richard Koval (6bombergroup.ca)
340 aircraft of 3, 4, 6 and 8 Groups - 170 Halifaxes, 127 Stirlings, 43 Lancasters - to attack the important railway yards at Modane on the main railway route from France to Italy. 5 American B-17s also took part. The marking of the target, situated in a steep valley, was not successful and the bombing was not accurate. No report is available from France. 2 Halifaxes and I Stirling lost.
source: The Bomber Command War Diaries, Martin Middlebrook and Chris Everitt