Complex sentence: In the evening of June 8th made contact with the convoy and attacked in the night, but all her approaches are frustrated by the escort and finally "U- 124" attacks the FFL "Mimose" and sinks her.
Split into simpler sentences: In the evening made contact with the convoy and attacked, but is frustrated by the escort. Finally "U- 124" attacks the FFL "Mimose" and sinks her.