This was almost our fourth mission but had trouble with one engine about half way to the target. We could not maintain formation so we had to turn back. Made the field OK but after we landed ran into a lumber truck and tore left wing tip off. It was a piece of tough luck for Borst. Early this morning we were briefed for a special mission of high importance - destroying a fort at Metz but it was cancelled before we took off for some unknown reason. The mission we started on was to Trier again. Maybe it is good we turned back because the boys were met with flak & fighters. Received 20 letters tonight - tomorrow we go to Paris for two days.