Complex sentence: The incident reportedly occurred shortly before 5:20pm on Friday, which is one of the busiest times of the week, when the crane fell into the east side of the mosque, with its boom crashing through the roof.
Split into simpler sentences: The incident reportedly occurred shortly before 5:20pm on Friday, one of the busiest times of the week. The crane fell into the east side of the mosque, with its boom crashing through the roof.