Police carry bags with the remains of children who burned to death in a bus, behind, in Fundacion in northern Colombia. Colombian authorities have detained the driver of the overcrowded bus that burned, killing 32 children. (AP Photo/Oscar Mejia, Hoy Diario del Magdalena)

Fundaciõn, Colombia - Tiny shoes and charred toys are still strewn along the road in Fundacion, Colombia, two days after a tragic bus fire claimed the lives of 33 children.

Sorrow and disbelief have overwhelmed inhabitants of this small northern Colombian town, as have anger and a yearning for justice.

“We want answers,” said Humberto Castro, inconsolable after losing four grandchildren in the tragedy.

“What they were transporting, it wasn't pigs. It wasn't livestock. They were babies,” Castro said.

The accident in this town of some 80,000 people occurred midday Sunday, as about 50 children between the ages of three and 12 were being driven home after Pentecostal church event.

When their rickety bus stalled, witnesses said the driver exited the vehicle with a petrol cannister in hand, leaving his young charges onboard.

In the torrid weather, and with the bus engine still running, the driver attempted to refuel the vehicle.

The gasoline somehow ignited, converting the vehicle into a giant fireball. Most of its young passengers, trapped inside, were burned alive.

The panicked, screaming children had no way to escape, and most lost their lives.

“One of my granddaughters was able to use her little foot to kick in the window and save one of her brothers,” Castro said.

The girl tried to rescue her other siblings, but “it was too late, they were already burned up,” he said.

Residents of Fundacion had tried to assist firefighters put out the blaze, but there was little to be done.

“We couldn't do anything but hold our heads and watch the children burn,” said Jose Guette, 48, who said he had tried in vain to put out the blaze with a fire extinguisher.

Officials said 13 children remained in the hospital, on Tuesday, most with second- and third-degree burns.

The tragedy occurred exactly one week before President Juan Manuel Santos, who visited the scene Sunday, stands for reelection in a May 25 election.

After the disaster, he ordered flags flown at half staff and has declared three days of mourning for the young victims.

Santos also has ordered a nationwide crackdown aimed at keeping unsafe vehicles off the road.

The disaster highlights the lamentable state of road safety in Colombia, where regulation and enforcement are spotty at best.

The bus in Sunday's disaster lost its operating permit in 2012, and had a catalogue of violations and irregularities, including no operational emergency exits.

The driver, meanwhile, who lost two of his own children in the disaster, had no valid license. He apparently also had used contraband gasoline to refuel the vehicle.

Officials said the man was taken into custody Sunday, as was the church leader who chartered the bus.

Residents of Fundacion said there was plenty of blame to go around, starting with, but not limited to, the driver.

“He drove around without saying anything, acting as if everything was normal,” said Jose Acosta, 21, a mechanic, as he carefully stepped among the broken glass and charred ground at the scene of the fire.

Acosta also faulted authorities who “don't do what they're supposed to do” when it comes to enforcing vehicle and road safety.

One rarely enforced regulation, said taxi driver Juana

Hernandez, is a prohibition against the transport of gasoline inside cars.

“Here in Fundacion, most people drive old cars,” said Hernandez, adding that it was not unusual for people to have a gasoline cannister inside their vehicle.

Fundacion's haunted residents, two days later, were unable to shake the grisly images of children's incinerated bodies being pulled from the bus.

“They were taken out completely burned Ä they were unrecognizable,” said Hernandez.

“Some of the children no longer had any limbs, others had their guts hanging out Ä it was really horrible,” she said.

Gina Rojas, medical coordinator at the clinic were many of the burn victims were rushed, said the facility has never had to cope with a disaster so tragic and overwhelming.

“This has caused so much pain for all of the personnel, the relatives Äeven the other patients,” who were overcome with grief, even as they were coping with their own medical emergencies, she said.

“Everyone was in tears.”