The 1970 Bhola cyclone was a devastating tropical cyclone that struck East Pakistan (present-day Bangladesh) and India's West Bengal on November 11, 1970. It remains the deadliest tropical cyclone ever recorded and one of the world's deadliest natural disasters. At least 500,000 people lost their lives in the storm, primarily as a result of the storm surge that flooded much of the low-lying islands of the Ganges Delta. Bhola was the sixth and strongest cyclonic storm of the 1970 North Indian Ocean cyclone season.