ABUJA, Nigeria, Sept 21, (AP): Houses swept away to the very last brick. Inmates frantically fleeing the city's main prison as its walls got washed away by water rising from an overflowing dam. Corpses of crocodiles and snakes floating among human bodies on what used to be main streets. As torrential rains across Central and West Africa have unleashed the most catastrophic floods in decades, residents of Maiduguri, the capital of the fragile Nigerian state of Borno - which has been at the center of an Islamic extremists' insurgency - said they have seen it all.

The floods, which have killed more than 1,000 people and displaced hundreds of thousands across the region this year, have worsened existing humanitarian crises in the countries which have been impacted the most: Chad, Nigeria, Mali and Niger. Over four million people have been affected by flooding so far this year in West Africa, a threefold increase from last year, according to the UN.

With rescue operations still underway, it is impossible to give an accurate count of lives lost in the water. So far, at least 230 were reported dead in Nigeria, 265 in Niger, 487 in Chad and 55 in Mali, which has seen the most catastrophic flooding since the 1960s. While Africa is responsible for a small fraction of global greenhouse gas emissions, but it is among the regions most vulnerable to extreme weather events, the World Meteorological Organization said earlier this month.

In sub-Saharan Africa, the cost of adapting to extreme weather events is estimated between $30-50 billion annually over the next decade, the report said. It warned that up to 118 million Africans could be impacted by extreme weather by 2030. Maiduguri, the capital of Borno state, has been under significant strain. Over the last decade, Borno has been hit by a constant string of attacks from Boko Haram militants, who want to install an Islamic state in Nigeria and have killed more than 35,000 people in the last decade.

Saleh Bukar, a 28-year-old from Maiduguri, said he was woken up last week around midnight by his neighbors. "Water is flooding everywhere!" he recalled their frantic screams in a phone interview. "They were shouting: ’Everybody come out, everybody come out!” Older people and people with disabilities did not know what was going on, he said, and some were left behind. Those who did not wake up on time drowned right away.