Complex sentence: When non-strikers attempted to report for work at 6:00 in the morning, the barricades went up and tensions flared as replacement workers to drive through the crowd and their cars were stopped and overturned.
Split into simpler sentences: When non-strikers attempted to report for work at 6:00 in the morning, the barricades went up and tensions flared. As replacement workers attempted to drive through the crowd, their cars were stopped and overturned.