Cyclone Bebe, which passed through the Tuvaluan islands in October 1972, submerged Funafuti and eliminated 90% of structures on the island. The storm surge created a wall of coral rubble along the ocean side of Fongafale and Funafala that was about 10 miles (16 km) long, and about 10 feet (3.0 m) to 20 feet (6.1 m) thick at the bottom.
Because of the low elevation, the islands of Tuvalu are vulnerable to the effects of tropical cyclones and by the threat of current and future sea level rise. The highest elevation is 4.6 metres (15 ft) above sea level on Niulakita.