Manila is hit with five to seven typhoons yearly. In 2009, Typhoon Ketsana (Ondoy) struck the Philippines. It led to one of the worst floodings in Metro Manila and several provinces in Luzon with an estimated damages worth ₱11 billion ($237 million). The floodings caused 448 deaths in Metro Manila alone. Following the aftermath of Typhoon Ketsana, the city began to dredge its rivers and improve its drainage network.