Next few hours will be critical in rescue operationpublished at 17:15 BST
Dan Johnson
Reporting from Cúcuta, Colombia
The situation in Venezuela is desperate.
There is a sense that the next few hours will be critical for saving anyone who is still trapped. People with search and rescue experience talk about a 72-hour window.
Around 2,000 search and rescue officials are heading into Venezuela from right across world - but getting people to the right area with the right equipment is a complex task.
Despite being in a risk zone, Venezuelan authorities were ill prepared for this sort of disaster - both in terms of building standards and the emergency response.
Political instability and corruption have contributed to an underfunded health system and search and rescue service.
There is widespread poverty, communications are difficult, and infrastructure is poor, meaning getting around the country is complex.
There are reports of tens of thousands missing - whether this translates into deaths will take time to see.
We will also have to see how open and transparent Venezuelan authorities are in terms of recording and reporting this information.
At the moment, the death toll still stands at less than 1,000 - the fear is that the total will climb significantly.




















