Complex sentence: On 12 February 1966, a communist attack overran Lima Site 27; on the 16th, they also attacked Lima Site 36, suffering heavy losses to napalm and to the fire of AC-47 gunships.
Split into simpler sentences: On 12 February 1966, a communist attack overran Lima Site 27; on the 16th, they also attacked Lima Site 36. Suffering heavy losses to napalm and to the fire of AC-47 gunships.