Marko Kokic of the International Federation of Red Cross and Red Crescent Societies reports from the Haitian town of Mapou, which lies almost entirely submerged by the flash floods that have claimed an estimated 900 lives in the region.
The only way into Mapou is by helicopter.
Locals gather on high ground, awaiting the arrival of essential aid (all photos: Red Cross)
As we touched down, we were immediately surrounded by hundreds of confused and grief-stricken villagers.
We were also assailed by the stench of death.
This village in south-eastern Haiti sits in a natural bowl, surrounded by mountains.
Now that bowl has been filled with floodwater, transforming the valley into an enormous lake.
Here and there, the roofs of homes in outlying areas poke out above the floodwaters.
An occasional corpse can also be seen.
We had come to Mapou on board a helicopter of the multinational force in Haiti to make an assessment of the levels of destruction and the needs of survivors.
We also brought essentials - thousands of water purification tablets, chlorine, medical kits, picks and shovels and body bags.
With aid agencies already active in the town of Fond Verrettes, the Haitian Red Cross, supported by the International Federation and the ICRC, is targeting this south-eastern area, which has so far received little assistance.
Survivors of the floods queue for aid: clean water is a priority
According to the latest figures, at least 638 people have perished in Haiti.
Many more have also died in the Dominican Republic, where the local Red Cross has also launched a concerted response.
The authorities say at least 173 people in Mapou have died as a result of the floods. Hundreds more are missing.
Many bodies have been buried without being identified.
With many homes still underwater, it is difficult to assess the exact number of dead.
It is likely that many of these humble dwellings contain the bodies of more people caught by surprise by the flash floods and landslides that devastated this rural community early on Monday morning.
The Red Cross is assessing the needs of the population
While water levels have dropped a little, the situation remains dangerous.
Some people have returned to home that are under threat from fresh flooding: the "lake" of floodwater is being held back by temporary dams of debris.
These could give way at any time, especially if, as is predicted for this weekend, more rain falls.
The priorities at the moment are to ensure that people are not living in areas that could be flooded again, and the removal of corpses to make sure that this natural catastrophe is not compounded by a public health disaster.
The Red Cross is bringing in inflatable dinghies fitted with outboard motors to search for cadavers - and possibly survivors - in the flood zone, and especially in those inundated homes.
'Where there was once a road, there is now a riverbed."
In flood situations like this, an important challenge is to prevent the spread of waterborne diseases, and during our mission to Mapou, we made sure that villagers were taught how to chlorinate their wells and purify water for drinking.
The relief efforts are being hampered by the lack of access.
Currently areas like Mapou can only be reached by helicopter, and all the helicopters in Haiti are working at full capacity to bring assistance to affected communities.
We had earlier visited the village of Toman, near Fond Verrettes, where we met Gerald Joseph, whose mother had died in the flood.
"We had had lots of rain on Sunday. Then, at three on Monday morning, we were caught by surprise by flash floods and landslides," he said.
"Our whole community is in a state of shock. Where there were once cornfields, there is now a lake. Where there was once a road, there is now a riverbed. We simply don't know what to do," he said.
On the way to Toman, we passed a 14-year-old girl, Emmanuelle Jeuni, who was being helped along the road by other people.
She explained that she, like many Haitians, had gone to the Dominican town of Jimani for its market.
The house she was staying in was washed away.
She had sustained a nasty gash to her arm and had received first aid from the Dominican Red Cross before crossing back into Haiti.
Emmanuelle managed to survive the deadly surge that swept through Jimani.
Many did not - even those close to her. Among those missing are her three younger siblings.
This article also appears on the website of the International Federation of Red Cross and Red Crescent Societies.