Hopes of finding survivors of Guatemala's El Fuego volcano's devastating eruption three days ago are now focused on six hamlets high up the mountain where people might just have found refuge from the super-heated wall of gas, ash, and mud that hurtled down from the crater and buried two whole villages further down.
"One million seven hundred thousand people are affected, and that number could rise - he said - there is serious damage to infrastructure, especially roads and bridges, so communications are very hard".
Mount Fuego is Spanish for "mountain of fire". In the small country, he helps train and advise the Guatemalan National Civilian Police for the U.S. Embassy. He said it was not immediately clear if some of those could be among the unidentified bodies.
At a shelter in the Murray D. Lincoln school in the city of Escuintla, about 10 miles (15 kilometers) from the volcano's peak, Alfonso Castillo said he and his extended family of 30 had lived on a shared plot in San Miguel Los Lotes where each family had its own home. The only thing they did not yet have was information on the unidentified bodies, but would be adding that as it became available, he said.
"We have some toiletries, like shampoo, toothpaste, toothtbrushes we are also including some cereral for the kids that are in shelters because we know they like them", said Geraldina Motta, director of Operation Blessing Guatemala.
The volcano shot ash and gas several kilometres up into the sky, which then fell back down and left debris across areas more than 15 kilometres away. My children say they would rather be in the streets.
It was covered in what he described as a "sea" of muck that came crashing into homes, smothering people, pets and wildlife. Rescuers are still digging, but not for survivors.
Diaz said it can be a kind of "consolation" for the displaced, many of whom will never be able to return to their homes.
"We now have an accounting with names and towns where people have gone missing and we have a figure, which is 192 people who we have unaccounted for", Disaster Relief Agency chief Sergio Cabanas was quoted as saying by AFP news agency. DNA testing and other methods will be required to identify them.
Officials said at least 69 people are dead and that figure is expected to rise possibly into the hundreds. "To see people suffering like this is hard on them".