Healthy reefs act as natural barriers, protecting coastal cities, communities, and beaches from pounding ocean waves. Without coral reefs, many beaches and buildings would become vulnerable to wave action and storm damage. With more frequent and severe storms predicted as part of climate change, these coastal protection services will become even more important. In the Indian Ocean tsunami of December 2004, some coastlines were spared further damage as a result of healthy reefs. In another instance, when coral and sand was mined away in the Maldives, it cost $10 million (USD) per kilometer to build a wall to protect the coastline (Wilkinson, C. and F. Talbot, 2001, Coral Reefs, Mangroves and Seagrasses: A Sourcebook for Managers).