first survivors to make contact with friends and family started to tell their horrifying stories.
Alexandre Berceaux worked for CIS Catering, the French company responsible for feeding more than 700 workers on the huge Tiguentourine site located in the desert in Algeria's deep south.
When dozens of Islamic gunmen launched their assault on the complex before dawn on Wednesday, he was in his room, his rest interrupted by the sound of an alarm going off.
From the security training all staff are given, he knew that the particular alarm meant he should stay put but initially assumed it was just a routine drill.
Repeated bursts of gunfire ensured he soon realised he couldn't have been more wrong and the Frenchman made a decision that may have saved his life.
Rather than trying to flee, Berceaux decided to stay in his room and hide under his bed, where he remained for 40 hours, praying the gunmen would not find him, before finally being liberated by the Algerian troops who stormed the site on Thursday evening.
"I was under the bed and I put boards everywhere just in case," Berceaux said Friday. "I had a bit of food, a bit to drink, I didn't know how long it would last."
Even when the Algerian forces arrived, Berceaux was reluctant to come out of his hiding place until he spotted fellow workers.
"I recognised some of my colleagues with them, otherwise I would never have emerged," he said.
When he did appear, he discovered that three Englishmen had survived in similar circumstances to himself having hidden in the space above a dropped ceiling.
Built by Japanese and American companies and operated jointly by Algeria's state oil company, Britain's BP and Norway's Statoil, the Tiguentourine complex had employees from all over the world.
Most of what happened when the Islamists stormed the complex and the subsequent army assault remained unclear Friday with efforts to completely liberate the site still underway.
But based on information filtering out, the gunmen attached explosives to many of the non-Algerian staff, apparently to ensure any army assault would result in a maximum number of casualties among the foreigners.
One of them was Stephen McFaul, a 36-year-old electrical engineer from Belfast who was part of a group which managed to escape when the Algerian army attacked a convoy of vehicles the Islamists were using to try and move some of the hostages to a different location.
According to Irish Foreign Minister Eamon Gilmore, McFaul said many of the hostages had belts of explosives strapped to them.
That confirmed the testimony of a French hostage who spoke to the France 24 television station by phone on Thursday evening and described how he was being held in a booby-trapped building along with English, Japanese, Filipino and Malaysian nationals, some of whom had been tied up and fitted with explosives.
McFaul's relieved relatives offered an insight into the agony suffered by family and friends and how, for many of the survivors, this will have been a life-changing experience.
"I can't wait till he gets home. I'm just going to say that he's never going back there, I'm not letting him go back," McFaul's 13-year-old son, Dylan, told Sky News.
His father, Christopher, added: "I feel sorry for the other hostages that are still there. We don't know what's happened to them, and the ones who have been killed -- I feel sorry for their families. The last 48 hours have been hell."