In this aerial photo inundated houses are seen in Sunamgong on July 15, 2020. Almost four million people have been hit by monsoon floods in South Asia, officials said on July 14, with a third of Bangladesh already underwater from some of the heaviest rains in a decade. / AFP / Munir UZ ZAMAN

A woman carries her sheep as she walks through flood waters in Sunamgong on July 15, 2020. Almost four million people have been hit by monsoon floods in South Asia, officials said on July 14, with a third of Bangladesh already underwater from some of the heaviest rains in a decade. / AFP / Munir Uz zaman

Children sit on a boat next a flooded house in Sunamganj on July 15, 2020. Almost four million people have been hit by monsoon floods in South Asia, officials said July 14, with a third of Bangladesh already underwater from some of the heaviest rains in a decade. / AFP / Munir Uz zaman

This aerial view shows flooded houses in Sunamganj on July 15, 2020. Almost four million people have been hit by monsoon floods in South Asia, officials said July 14, with a third of Bangladesh already underwater from some of the heaviest rains in a decade. / AFP / Munir Uz zaman

In this aerial photo inundated houses are seen in Sunamgong on July 15, 2020. Almost four million people have been hit by monsoon floods in South Asia, officials said on July 14, with a third of Bangladesh already underwater from some of the heaviest rains in a decade. / AFP / Munir UZ ZAMAN

Women and children use a boat to make their way through floodwaters in Sunamganj on July 15, 2020. Almost four million people have been hit by monsoon floods in South Asia, officials said July 14, with a third of Bangladesh already underwater from some of the heaviest rains in a decade. / AFP / Munir Uz zaman

This aerial view shows flooded houses in Sunamganj on July 15, 2020. Almost four million people have been hit by monsoon floods in South Asia, officials said July 14, with a third of Bangladesh already underwater from some of the heaviest rains in a decade. / AFP / Munir Uz zaman

A house is seen under floodwaters in Sunamganj on July 15, 2020. Almost four million people have been hit by monsoon floods in South Asia, officials said July 14, with a third of Bangladesh already underwater from some of the heaviest rains in a decade. / AFP / Munir Uz zaman

A man stands outside his flooded house in Sunamgong on July 15, 2020. Almost four million people have been hit by monsoon floods in South Asia, officials said on July 14, with a third of Bangladesh already underwater from some of the heaviest rains in a decade. / AFP / Munir Uz zaman

This aerial view shows flooded houses in Sunamganj on July 15, 2020. Almost four million people have been hit by monsoon floods in South Asia, officials said July 14, with a third of Bangladesh already underwater from some of the heaviest rains in a decade. / AFP / Munir Uz zaman

A child stands in front of a flooded house in Sunamganj on July 15, 2020. Almost four million people have been hit by monsoon floods in South Asia, officials said July 14, with a third of Bangladesh already underwater from some of the heaviest rains in a decade. / AFP / Munir Uz zaman

A man stands inside his flooded house in Sunamgong on July 15, 2020. Almost four million people have been hit by monsoon floods in South Asia, officials said on July 14, with a third of Bangladesh already underwater from some of the heaviest rains in a decade. / AFP / Munir Uz zaman

A man works on a boat as a boy walks through flood waters in Sunamgong on July 15, 2020. Almost four million people have been hit by monsoon floods in South Asia, officials said on July 14, with a third of Bangladesh already underwater from some of the heaviest rains in a decade. / AFP / Munir Uz zaman

People make their way through flood waters in Sunamgong on July 15, 2020. Almost four million people have been hit by monsoon floods in South Asia, officials said on July 14, with a third of Bangladesh already underwater from some of the heaviest rains in a decade. / AFP / Munir Uz zaman

Local people carry a sea turtle to release it into the sea in Cox's Bazar on July 12, 2020. About 160 sea turtles, many of them injured after getting entangled in plastic waste, have been rescued after washing up on one of the world's longest beaches in Bangladesh, an official and conservationists said on July 15. / AFP / Suzauddin RUBEL

In this aerial photo inundated houses are seen in Sunamgong on July 14, 2020. Almost four million people have been hit by monsoon floods in South Asia, officials said July 14, with a third of Bangladesh already underwater from some of the heaviest rains in a decade. / AFP / Munir UZ ZAMAN

A man stands in front of his flooded house in Sunamgong on July 15, 2020. Almost four million people have been hit by monsoon floods in South Asia, officials said on July 14, with a third of Bangladesh already underwater from some of the heaviest rains in a decade. / AFP / Munir Uz zaman

In this video grab taken from the Associated Press Television footage Bangladeshi men with a goat row a banana raft through flood waters in Lalmonirhat, Bangladesh, Monday, July 13, 2020. Heavy flooding is worsening in parts of Bangladesh, with over 1 million villagers marooned or leaving their homes for higher ground along with their cattle and other belongings, officials and volunteers said Tuesday. (AP Photo/Bayezid Ahmed)

In this aerial photo inundated houses are seen in Sunamgong on July 14, 2020. Almost four million people have been hit by monsoon floods in South Asia, officials said July 14, with a third of Bangladesh already underwater from some of the heaviest rains in a decade. / AFP / Munir UZ ZAMAN

People ride on a boat through flooded waters in Sunamgong on July 14, 2020. Almost four million people have been hit by monsoon floods in South Asia, officials said July 14, with a third of Bangladesh already underwater from some of the heaviest rains in a decade. / AFP / Munir Uz zaman