Complex sentence: On February 3,1931, Napier and Hastings were devastated by New Zealand's worst natural disaster, an earthquake measuring 7.9 on the Richter Scale, which killed 256 people.
Split into simpler sentences: On February 3,1931, Napier and Hastings were devastated following New Zealand's worst natural disaster. An earthquake measuring 7.9 on the Richter Scale killed 256 people.