Complex sentence: Meanwhile, at Shanghai proper, Chinese Air Force Northrop 2E light attack bomber aircraft had tried to bomb Japanese positions in their portion of the International Settlement; the bombs fell short and caused extensive damage and heavy loss of life in the neutral portion of the settlement.
Split into simpler sentences: Meanwhile, at Shanghai proper, Chinese Air Force planes, Northrop 2-E light attack bombers, had endeavored to drop bombs on Japanese positions in their portion of the International Settlement. They fell short and caused extensive damage and heavy loss of life in the neutral portion of the settlement.