As a siren echoes across this desert outpost crowded with people awaiting a miracle, Silvia Gomez begins to sob.
Authorities have said families should expect a siren to sound when a trapped miners is just seconds from reaching the surface of the San Jose mine, where 33 men have been locked below for more than two months.
This siren comes from a passing ambulance. It's a false alarm. But it is, for the waiting families, a certain indication that they are nearing the end of a months-long wait for 33 miners, trapped more than half a kilometre below the earth in a tomb that, they hope, is about to open.
"So much time we've been waiting," Ms. Gomez says through the tears.
Her brother, Mario, remains below, but could be freed within the next 48 hours.
"Always we thought he was alive. Always. Now it's the end. But it's missing the most important part."
Authorities have also named the first three men who have been chosen for rescue: Florencio Avalos will be first, Mario Sepulveda will be second and Carlos Mamani, the sole Bolivian amid the group, third. The last will be Luis Urzua, the mine foreman.
In an interview earlier Tuesday, an uncle to Mr. Avalos said he has already decided what to tell his nephew if the rescue is successful: "I have so much to say. Like, that we were here the whole time and the pain we felt," said Alberto Avalos.
Mr. Avalos is 31, and is second in command of the mine, where he has worked for three years to save up money for his two children to attend university. His brother, Renan, is also in the mine. He was chosen as first for his age - his youth is seen as an advantage for the stressful trip - and his skills as a capable miner.
Local media have reported that Chilean president Sebastian Pinera has arrived at the mine site, another sign that the rescue effort, which is expected to begin this evening, is imminent. Mr. Pinera will spend the afternoon meeting with the families - some, including Ms. Gomez, have been requested to spend some time with him - and is expected to also greet rescue crews on the most important moment in their months-long effort.
The camera crews are still hustling down the gravel streets, and the forest of Chilean flags is still flapping in the wind, but a nervous quiet has descended over Camp Hope, as the final countdown to a rescue attempt for 33 trapped miners begins.
"We are just a few hours to start this process," Chilean mining minister Laurence Golborne said Tuesday.
Crews poured a concrete pad overnight designed to support a winch that will lift the miners to surface. That concrete is now cured, and workers are installing the winch, the final piece of equipment that needs to be installed before the rescue can begin. That installation is just hours from being completed, Mr. Golborne said just before 1 p.m. Chilean time Tuesday.
After that, workers will spend two or three hours testing an escape capsule before sending down the first rescuer - and soon after, they hope, bring the first miner back to surface.
The rescue attempt will start "as soon as everything is ready to do it in the safest way," Mr. Golborne said, as families, many of them bleary-eyed after a sleepless night, huddled in tents and paged through Bibles, sorting through the anxious emotions of the final wait.
Government officials declined to give a time, but said the "final journey" would begin in the "last quarter" of the day. The entire country - and indeed, much of the world, which will see the effort broadcast live - has been waiting for this moment. Chilean president Sebastian Pinera himself is waiting, ready to travel to the mine the moment engineers determine they are ready.
"It will be a long day today. The wait will be long," said Fabiola Araye, who is waiting for trapped husband Claudio Acuna.
This day has take more than two months to arrive, a time that has seen hundreds of family members join Ms. Araye in a sometimes hellacious emotional ride- from fears that the men were dead, to the joy that they were found alive, to the ecstasy when an escape shaft reached them this weekend.
Yet mixed with it all remains the knowledge that in many ways the most delicate and dangerous part of the operation remains ahead. In the next few hours - although it could be less if things go well - workers will attempt to move a human being 622 metres inside a narrow, winding hole, through a mine that has proven itself prone to collapse, in an area that is prone to earth tremors.
And they must repeat the feat at least 38 times - 33 times to bring up the men, and a further five times to lift the rescue workers, who will descend in two sets: three at the outset, then another two at the 12-hour mark.
"The first days, I felt terror," said Ms. Araye. "It's a bit more calm now, but I have a few fears of the rock. Every rescue has risks."
Those fears had been largely muted in the past few days, amid the raucous carnival that erupted at the mine when first a rescue shaft successfully the miners, then the first test of an escape capsule was conducted without problem. On Tuesday, Mr. Golborne sought to calm worries about a possible disaster.
"We have hundreds of different contingencies, and we have established different procedures to do it," he said. "There is no need to try to start guessing what could go wrong. We have done that job."
Still, he admitted: "you never know what could go wrong."
But if the quiet of the last few hours, has made it impossible not to cast a thought to the difficult work that remains, it has also hastened the hour when most families expect to celebrate as they have never before.
It's a feeling that has permeated even the youngest who stand in wait. Sitting next to Ms. Araye, her two-year-old daughter voices the words on everyone's mind: "Papa! Papa!"
"She knows he's coming home from work," Ms. Araye said.
Though the first miner is expected to be rescued this evening, families have determined to stay together at the mine until the last is out in a show of solidarity, Ms. Araye said.
"I feel nervous in my stomach," said Roberto Reyes, whose uncle, Mario Gomez, is the oldest man stuck beneath the earth.
"This week, I've slept very little. When this is all over, I'll sleep for a long time."
Government officials have said it could take each man anywhere from 11 minutes to an hour to come to surface - and have warned that the entire rescue, if it is successful, could take as long as 48 hours from the moment it begins.
But families have grown accustomed to workers exceeding the worst-case scenario - the government, after all, initially warned that it could take until Christmas to begin the rescue - and have set their hopes on a rapid timeline.
"I think it's going to happen much earlier than what they said, because this rescue is full of surprises," said Alberto Avalos, who has two nephews, Renan and Florencio, in the mine.
That is, if anyone will be able to hear those words amid the celebrations that have been planned.
On Tuesday, a small truck emblazoned with "Mundo Fiestas" - "World of Parties" - parked at the mine site. Inside are hundreds of joker hats, coloured in the red, white and blue of the Chilean flag.
Sebastian Henriquez drove the van eight hours from Santiago to be here.
On Tuesday, though, he will keep the van locked, the hats safely inside until the first miner is rescued.
"It is a time to wait," he said.
-with files from Eva SalinasReport Typo/Error