Prosecutors arrived to the remote Italian village Saturday to investigate why a school collapsed in a powerful earthquake, killing 29 people, nearly all of them children, while adjacent buildings remained standing, although damaged.

Traumatized survivors, meanwhile, spent a fearful first day Saturday in a tent city in the hills, constantly in fear that the earth could again heave below them.

About 900 residents had moved into the camps set up in this olive-oil producing southern Italian region, but some were allowed to return to their homes briefly Saturday to gather some belongings, accompanied by firefighters.

Authorities said the investigation was focusing on possible charges of negligence or manslaughter but it remained unclear who, if anyone, could face criminal penalties for the building's collapse, which killed 26 children and three adults.

"We have to ascertain if there's possible responsibility," said prosecutor Andrea Cataldi Tassone, noting it was unusual for an entire building to collapse while those around it were damaged but remained standing.

The immediate issue for many residents, however, remained shelter, food and other aid after Thursday's 5.4-magnitude earthquake and the series of terrifying aftershocks. More than 3,000 people across several towns in the area remained homeless.

Aid officials set up blue tents to house San Giuliano's population of about 1,200 people, who were evacuated Friday after their cracked and crumbling homes were deemed unsafe.

An unshaven, haggard survivor said he couldn't believe he was living as a refugee. "We've seen these scenes on television, and now we find ourselves in a tent camp," Giuseppe Iacurto said.

"My son was in the school when it came down. He was one of the first pulled out. Two of my nephews were killed," he said.

His son, 10-year-old Paolo, bore a thick gash on his forehead and another scar on his leg. Paolo said he was still afraid, and had leapt up in the night thinking he'd felt another quake.

"When I was sleeping I heard shaking," he said. "I woke up and it was only some trucks going by."

A mild aftershock hit the area before dawn Saturday, a day after two strong aftershocks -- one registering 5.3 magnitude -- rumbled through town, sending panic-stricken residents into the streets.

"Up until the aftershocks, people were reluctant to move," said Mario Fredianelli, a senior civil defense worker at the San Giuliano tent camp.

"Following the aftershocks, they were willing to move, except for some old people in the historic center. We had to use the police to move them by force."

He said about 90 percent of the town's buildings were uninhabitable.

"It will take time to rebuild it. I don't know how long people will be here," he said, referring to the tent city.

Rescue workers extracted the last body Friday from the rubble of the school where the 26 children and one teacher died. Two town residents were killed in their homes Thursday.

Recriminations have come to the surface, with anger that the area -- about 140 miles southeast of Rome -- had not been designated a quake zone, which meant its buildings didn't have to be built to withstand temblors.

Funeral services were scheduled for Sunday. In the meantime, a gymnasium outside the crumbled San Giuliano town center was converted into a morgue. A few blackened, lifeless baby faces peeked out of the open caskets above basketballs, photos, and soccer jerseys.

The school itself -- which along with the rest of town has been completely sealed off -- was a 35-foot pile of stone and bent metal littered with "Puss N' Boots" books, an "E.T." pencil case, backpacks and a sneaker.

The investigation reflected the question among many in Italy about why the 50-year-old yellow complex, which housed a nursery, elementary and middle school, collapsed.

The ANSA news agency reported that a second story had been added to the original structure in recent years and that renovations were carried out two years ago in which heavy cement was applied to the structure to try to reinforce it.

In addition to the structural questions, the last time authorities updated quake plans for the region, San Giuliano was not considered at-risk for strong earthquakes, engineer Enzo De Crescio told private TG5 television. The school, he said, did not meet earthquake safety standards.

Enzo Boschi, president of the National Institute of Geophysics and Vulcanology, said the region should certainly be considered at-risk for quakes, and urged residents to demand their mayors designate it as such.

More dislodged families trickled into the tent camp Saturday, some with T-shirts, underwear and any other necessities they could pile into a car. One family carried a small brown rug, apparently to make their tent feel a little more homey.

The large tents, housing about six people each, were bare and sterile inside, with cots and portable radiators. Outside, on what was once a soccer field, kids kicked about a ball amid police, soldiers and volunteers, while the elderly sat by a wooden cross. A few parents kept their children distracted with coloring books.

Survivor Alessandro Astore, who was in the tent camp with his wife and baby, was desperate to get out.

"It's disgusting," he said. Pointing to his child in a carriage, Astore added, "I have a little girl here who's one month old."

Civil defense official Fredianelli said the survivors were in a state of shock.

"They've lost all the things that are dear to them," he said. "They can't see a certain future."