Updated at 11:02 p.m. ET
Around midday Sunday, the bright blue sky less than 30 miles southwest of Guatemala City darkened to a billowing gray — and with a vicious rumble, one of Central America's most active volcanoes stirred to life again. Mount Fuego spewed ash and lava from its heights, blanketing the lands nearby and leaving at least 69 people dead, according to Guatemala's National Institute of Forensic Sciences.
Many people were injured and, with others still missing, Guatemalan authorities fear the death toll may rise further as the aftermath from the sudden eruption becomes clear. More than 3,200 people have evacuated the area.
"It is too early to know the full extent of the damage," President Jimmy Morales said in a statement posted to Facebook. And, as rescue workers sought survivors in the pale gray just miles from his presidential palace in the capital, Morales added that it is a time for Guatemalans to come together in "unity, prayer and solidarity."
He has declared three national days of mourning.
Guatemala's national disaster response agency, CONRED, said overnight that the eruption lasted more than 16 hours before finally quieting. The agency described the substance ejected by the volcano as a pyroclastic flow — defined by the U.S. Geological Survey as "a high-density mix of hot lava blocks, pumice, ash and volcanic gas."
The USGS adds that pyroclastic flows, which resemble avalanches in their overwhelming rush, can reach temperatures of up to 1,300 degrees Fahrenheit and speeds of more than 50 mph. They can "knock down, shatter, bury or carry away nearly all objects and structures in their path," the service notes.
"It's a river of lava that overflowed its banks and affected the El Rodeo village. There are injured, burned and dead people," CONRED General Secretary Sergio Cabañas said on radio.
Eddy Sánchez of the country's National Institute of Seismology, Volcanology, Meteorology and Hydrology told the newspaper Diario de Centro América that thick black smoke and ash also fell for miles around the volcano — including in San Lucas, Antigua Guatemala, Alotenango, Chimaltenango and Zaragoza.
Most of the victims reported initially were from the village of El Rodeo, according to Guatemala's El Periódico newspaper.
"The only thing we could do was run with my family and we left our possessions in the house," El Rodeo resident Efrain Gonzalez told the BBC. "Now that all the danger has passed, I came to see how our house was — everything is a disaster."
Pyroclastic flows move quickly, and in Fuego's case, the fiery rivers loosed by Fuego surprised many victims with their speed.
"Not everybody could escape," said another El Rodeo resident, Consuelo Hernández, according to El Periódico. She spoke to a TV crew as she walked down road loud with sirens, dazed and as layered in ash as the busy roadway she was crossing. "I think they were buried."
The eruption Sunday was Fuego's second this year, according to CONRED, though the first incident, in February, left far less of an impact.
Shortly after the scale of the devastation became clear, other leaders from around the world offered their condolences and words of support on Twitter.
"All our solidarity and support to the President Jimmy Morales and the Guatemalan people for the loss of human life," Mexican President Enrique Peña Nieto tweeted Sunday.
The foreign ministry in Israel, where Guatemala recently became one of the few countries to move its embassy to Jerusalem, announced that Israel would be sending emergency aid, including food and medicine.
"Guatemala," the ministry announced, "Israel stands with you!"
In the meantime, Guatemalan authorities remained at work on what could be a daunting rescue effort. As of midday Monday, CONRED said the deadly eruption has affected more than 1.7 million people.
RACHEL MARTIN, HOST:
A volcano in Guatemala erupted Sunday, sending ash, lava and deadly gases down a mountainside near the capital. More than 20 people died. Hundreds are injured, and officials fear casualty numbers will rise. NPR's Scott Neuman has more.
SCOTT NEUMAN, BYLINE: Appropriately enough, the name of the volcano Fuego means fire in Spanish. And video from the scene makes it clear that Mount Fuego, one of the most active volcanoes in Central America, is living up to its name.
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CONSUELO HERNANDEZ: (Speaking Spanish).
NEUMAN: Consuelo Hernandez is from the village of El Rodeo, directly in the path of the eruption. On a road leading away from the volcano, she was interviewed by a reporter for Diario de Centro America newspaper. Covered in ash and obviously exhausted and distraught, she says she and others ran toward a hill to escape a mudslide triggered by the eruption. "Not everyone was able to get out," she says. "I think they were buried." It's too early to tell the scale of the disaster, but emergency officials in Guatemala say the eruption could ultimately affect more than 1 1/2 million people. Guatemala's president, Jimmy Morales, has declared three days of mourning for the dead. Scott Neuman, NPR News.
(SOUNDBITE OF HAUSCHKA'S "CRACO") Transcript provided by NPR, Copyright NPR.