At least 54 people have been killed and scores more injured after the truck they were being transported in crashed in southern Mexico, authorities say.
More than 150 people, said to be migrants from Central America, were crammed into the truck’s trailer when it rolled in the state of Chiapas.
One resident heard a man implore his badly hurt companion: “Remember what you promised your mother! Hold on.”
Pictures show victims strewn across the road next to the overturned truck.
Sabina Lopez, who lives nearby and ran to the scene after the crash, told the AFP news agency that she saw dozens of people screaming in pain, some trapped in the wreckage and others unconscious.
“It was horrible to hear the wailing. I just thought about helping,” Ms Lopez, 18, told AFP.
She said the impact of the crash had broken the container in half and ripped off its roof.
Isaias Diaz arrived 15 minutes after the crash and helped paramedics with those people showing signs of life.
“I saw five, six children who were clearly injured. People with broken legs, ribs, [injured] heads, cuts on their necks,” he told AFP.
“The crying, the pain, the despair. It was a terrible scene,” he added.
Residents offered crash survivors water and mobile phones to contact relatives. They also said the driver and a person with him appeared injured, but then fled.
It is one of the worst accidents of its kind in Mexico. Forty-nine people were confirmed dead at the scene and five more died in hospital, Chiapas Governor Rutilio Escandón said.
Some 105 people – 83 men and 22 women – were also injured in the crash, he said.
Emergency officials said the victims included men, women and children. Most of the people on board were from Guatemala, but there were others from Honduras, Ecuador and the Dominican Republic.
The truck was reportedly speeding when it flipped on a sharp bend and hit a pedestrian bridge on a main road leading to the Chiapas state capital, Tuxtla Gutiérrez, at about 15:30 local time on Thursday.
Chiapas, which neighbours Guatemala, is a major transit point for undocumented migrants.
Hundreds of thousands of migrants fleeing poverty and violence in Central America try to cross through Mexico each year in a bid to reach the US.
Many of them pay smugglers, who illegally transport them in crowded and dangerous trucks on the long journey.
Human rights groups recently criticised the Biden administration for reinstating a Trump-era border policy requiring asylum seekers to wait in Mexico while claims are processed. The policy has meant that thousands of migrants have been forced to stay in dangerous towns.
The US-Mexico border is the deadliest single crossing in the world according to data from the International Organization for Migration (IOM). This year alone, at least 650 people have died trying to cross the border – more than in any other year since IOM’s records began.
There are also many deaths on the perilous journey towards the border, however these are harder to accurately document, the IOM said in a statement.
Mexico’s President Andrés Manuel López Obrador described the crash as “very painful” and wrote on Twitter that he “deeply regrets the tragedy”.
In a news conference early on Friday, Mr López Obrador said the incident would be investigated and that it served to raise awareness of the need to address the causes of migration through Mexico.
Last month, a migrant caravan heading through Chiapas found that the local authorities had clamped down so hard on people providing lifts to migrants, they effectively had to undertake the entire journey on foot.
That meant carrying their children in their arms in the blistering heat and torrential downpours of southern Mexico’s rural states.
It’s a tactic employed by the government to try to break the migrants’ will, to see if any will give up and turn back or accept asylum conditions in Mexico.
Throughout it all, trucks have continued to transport thousands of migrants right under the noses – or with the complicity – of the state authorities.
Their trailers filled with scores of families standing in cramped and unsafe conditions for hours, it’s a wonder such incidents aren’t more frequent.
Often the biggest danger to the migrants is from suffocation as the people-smugglers fail to provide sufficient ventilation or hydration for the trip.
Yet most of those in this horrific crash came from Central America and will have been escaping economic ruin, the effects of severe weather from climate change on their livelihoods or gang violence. Or some combination of all of these factors.
With that in mind, many thousands more will continue to consider the dangers of the road to be a risk worth taking to flee the unbearable conditions at home.