Complex sentence: Three buildings in Nagano Prefecture and Okinawa Prefecture were destroyed completely and, in the same prefectures, eight buildings were partially destroyed, and altogether, 19 buildings took damage in Okinawa Prefecture.
Split into simpler sentences: Three buildings in Nagano Prefecture and Okinawa Prefecture were destroyed completely and, in the same prefectures, eight buildings were partially destroyed. Altogether, 19 buildings took damage in Okinawa Prefecture.