Survivors saw relatives swept away by huge waves or buried by debris after a huge landslide hit a rain-swollen river, triggering waves that essentially wiped a Chiapas hamlet off the map and left at least 16 people missing.
Residents of San Juan Grijalva said on Monday they had been awakened by a rumbling roar and the sound of rocks rolling down from surrounding mountaintops on Sunday night, almost a week after massive flooding sent rivers over their banks in the southern Mexican states of Chiapas and Tabasco.
"It was a roar, like a helicopter was passing overhead," farmer Domingo Sanchez, 21, said. "We didn't know what was happening, and then we went outside, and there were cracks opening the earth," he said, apparently recounting the initial collapse of a nearby hillside into the river. "We ran up the hill ... but soil kept coming down on us."
For the next several hours, Sanchez, his mother, his wife and a cousin fought for their lives in a valley where the only salvation lay in getting to higher ground as the ground collapsed around them.
They reached the hilltop just in time to look across the valley and see a landslide cover the home of his grandparents. Sanchez believes at least nine of his relatives were buried.
A cousin, David Sanchez, 22, described the events he saw from his house in a different part of the village that once was home to about 600 people.
David Sanchez described two distinct waves -- the first of which swept his mother about 200m downstream before he could rescue her.
"It was an irresistible wave," he said, describing the water pushed downstream from the initial impact of the landslide.
After climbing up a hillside to safety, he and three friends briefly descended to rescue some possessions when the second wave -- apparently the release of water briefly dammed up by the landslide -- swept down the valley.
"It swept away everything, trees, houses, everything," said David Sanchez, who believes that a total of about 40 people died in San Juan Grijalva.
Chiapas State Governor Juan Sabines, who visited the scene, described one of the waves as a "mini tsunami," adding "this village practically disappeared."
Helicopters searched the surrounding hills to rescue residents who fled to higher ground.
Chiapas officials and the federal Interior Department placed the number of missing at 16.
The landslide was the latest blow after a week of devastating flooding and heavy rains that left 80 percent of Mexico's Gulf coast state of Tabasco under water, destroying or damaging the homes of about half a million people.
On Monday, officials readied huge pumps to suck water from the inundated streets of the state capital, Villahermosa, while rescuers struggled to reach thousands still stranded days after one of the worst floods in Mexico's history.