Complex sentence: The Europeans finally had won free pass at a cost of 28 dead and 95 wounded, and suffering severe damages that left their fleet stranded at Obligado for 40 days to make emergency repairs.
Split into simpler sentences: The Europeans finally had won free pass at a cost of 28 dead and 95 wounded. The ships suffered severe damage that left them stranded at Obligado for 40 days to make emergency repairs.