Complex sentence: Emotionally broken, all three slump into a fatalistic depression in the F-unit's cab, only to be shattered when Ranken's accomplice crashes through the second engine's window and is killed after unsuccessfully trying to board the lead engine via helicopter.
Split into simpler sentences: Emotionally broken, all three slump into a fatalistic depression in the F-unit's cab. Suddenly Ranken's accomplice crashes through the second engine's window and is killed after unsuccessfully trying to board the lead engine via helicopter.