Special sonar equipment and tracker dogs were at work as the chance of finding survivors decreased. The rescue effort was hampered by a fire underneath the ruins, covering the scene in a veil of smoke, believed to be coming from inside the ruins of the building.
At least 21 people were confirmed dead last night, but the toll was expected to rise. The building housed 24 families, and more than 75 people were thought to be in it when it crumbled. Nine people have been pulled alive from the rubble, including two children. Many were treated for shock but none is seriously injured.
Thousands of relatives waited in clusters at the site for news of loved ones. Neighbours of five similar apartment complexes watched from their balconies as firefighters and soldiers toiled in a jumble of concrete.
What was once a tidy 120ft high brick structure is now 30ft of twisted rubble, with the mass of the building sucked into the subsoil. A huge concrete pillar lies on top of the wreckage, alongside it a kitchen sink and a bathroom cabinet, and other shreds of everyday life. Cars shattered with mortar and covered by dust have been towed to one side. Two immense cranes stand idle as using them could create further damage.
"My brother's under there, and his four kids and another nephew," said Domenico, an agricultural worker, as he wiped his hands and fiddled with his acrylic maroon sweater. "He's just 40 and the children are all teenagers." His wife, fighting back the tears, added: "Our only hope is God."
A pensioner, Antonio La Riccia, had brought along a deck chair and refused to move while the search continued. The parents-in-law of his son lived in the apartment building. His son, wearing a mask and red overalls, is among the countless figures swarming over the ruins in search of some sign of life. "You just don't expect it. Here we are nearly in the year 2000 and boom, an apartment block just crumbles like a sandcastle" he said, shaking his head in bewilderment.
The tragedy happened just after 3am yesterday. The Torraco family, on the ground floor, heard sounds that alarmed them and they rushed next door to alert the administrator of the apartment complex, Luigi Lacontana. He called the fire brigade and then buzzed all the apartments to tell them to get out. "I just had time to step back and look up to the windows to see who was turning on the lights when it all began to disintegrate and I ran for my life."
A survivor, Salvatore Taronna, 19, said from his hospital bed: "In the heart of the night I heard my bed shake, like an earthquake. Then I heard creaking noises but I couldn't understand what was happening. All of a sudden I found myself deep in chunks of cement. It was dark and I didn't have the strength to scream."
Another survivor, Aldo Guidone, said his son and daughter-in-law felt the floor tremble, then heard their doorbell ring. The next thing they knew, they were lying amid rubble. Their eight-year-old son is missing.
One family of five heard creaking, saw a hole open up in their kitchen floor and ran. They rang neighbours' doorbells to warn them, but the building crumbled in a cloud of dust before they saw anyone else get out.
Yesterday afternoon, firefighters heard the voice of 15-year-old Angelo, who was injured and trapped beneath the rubble but protected in a niche. "I'm thirsty." he said as the firefighters tried to reassure him. He was pulled out to cheers and applause yesterday evening.
But as night fell, the number of blue plastic body bags being taken from the site out numbered those limp but living figures on the ambulance stretchers.
Magistrates in Foggia have opened an official investigation into the tragedy. The building was built in the late Sixties, at the start of Italy's economic boom, when the desire to provide reasonable housing quickly meant the use of poor materials, unsuitable sites and dodgy practices. A similar collapse of a building in Rome late last year killed 27 people, including six children. The cause of that collapse was structural failure.
There were reports that there had been complaints in Foggia of cracks in the wall of the building and concern about restructuring work done in the lower floors. The man who built the apartment is among those trapped in the wreckage.
Another hypothesis in the tragedy is that the ground beneath the block gave way. This has been supported by the local seismic observatory.
The observatory's director, Federico Negri, said it had registered a sudden earth movement, not identifiable as an earthquake, but rather as subsidence shortly after 3am.
The Italian Prime Minister, Massimo D'Alema, visited the site of the tragedy yesterday afternoon, and announced that a state of emergency would be declared in Foggia today.
"We need to discover the causes and the responsibilities for this tragedy as soon as possible," he said at the site of the collapse.