Complex sentence: Both bombs were still active, and it took a number of days to deactivate them, as this was very risky work, proven on the 24th May when sank after an unexploded bomb detonated while experts were attempting to deactivate it.
Split into simpler sentences: Both bombs were still active, and it took some days to deactivate them. This was very risky work, as demonstrated on 24 May when sank after an unexploded bomb detonated while experts were attempting to deactivate it.