Complex sentence: This wave action came within 10 minutes of the earthquake and was followed by shortly after by two larger waves that were separated by about 15 minutes and destroyed all the buildings that were made of woven grass and corrugated metal roofs.
Split into simpler sentences: This wave action came within 10 minutes of the earthquake and was followed shortly after by two larger waves that were separated by about 15 minutes. These waves destroyed all the buildings that were made of woven grass and corrugated metal roofs.