By Margo Pfeiff, March 2007

Efrain Alberto Del Valle felt hot in his overalls, gloves, mask and goggles, but around him it looked like a snow cave, caked with cement.

The 44-year-old from Colombia had just finished lunch and was back inside a clogged, 27m-high cement powder silo at the Federal White Cement company near Woodstock, Canada. Along with his 18-year-old son, Efrain, Jr, he'd been hired to chip away at hardened powder blocking the flow through the hopper at the bottom of the silo. The rocklike material formed a floor that sloped like a cone ten to 20m down into the silo, a seemingly solid surface on which three men stood using sledgehammers, a pneumatic drill and shovels to break the rock into powder. This day, August 28, 2004, was their last on the job.

At 2.30pm Efrain was shovelling rubble up to his co-workers from inside a trench at the deepest point inside the silo when suddenly the ground beneath him gave way. To his horror, he had broken through to an air pocket, and before his slack safety rope could catch him, he was knee-deep in dust. He struggled to free himself, but each movement he made sent fine powder flowing towards him from above like sand in an hourglass. Within minutes he was buried to his waist. The air, thick with cement dust and caustic lime, was burning his throat and forcing him to keep his eyes shut. When two co-workers rushed down to dig him out, they set off an avalanche of rocklike clumps. "No! No! Stop!" he yelled. "You're burying me."

By the time Efrain, Jr, who had been working outside, scrambled through an entry hatch on the silo roof to see what was going on, his father far below was buried to his armpits, with just his head and arms exposed. Efrain, Jr, knew he was the only one who could reassure his terrified dad, who spoke very little English. "Stay calm," he urged him in Spanish from a ladder leading down into the silo.

Co-workers on the roof quickly set up a tripod and winch system over a second hatch directly above Efrain and lowered a steel cable. Unable to open his eyes, Efrain fumbled to clip the line to his harness.

"Tell them to pull me up," he told his son. The winch began to tug on his harness and a terrible pain shot through Efrain's body, yet he said nothing he was so desperate to get out. But soon the rescue attempt had to be abandoned. Efrain was in too deep. "Hold on, Dad!" Efrain, Jr, shouted. "They're calling 911."

Don Shewan, chief of the local Embro Volunteer Fire and Rescue Department, reached the top of the silo around 3pm and saw another reason why workers had cut short their rescue: the victim was literally hanging by a thread, the cable now frayed to a single strand. Shewan peered into the silo, but his view of Efrain was partially blocked by a ledge of hardened cement extending almost 2m in from the wall.

The victim was directly beneath the overhang, wedged into a funnel of cement debris. Shewan knew the rescue would be more technical than his men could handle. As his crew lowered water and a breathing apparatus to Efrain, he radioed for specialised help.

Captain Mike Black was mowing his lawn that balmy Saturday afternoon when he received the call. As leader of the London Fire Department's Technical Rescue Team, he knew it was a dangerous assignment. In addition to the four firefighters on duty, he called in five with technical rescue training. Sirens screaming, two fire trucks raced the 30km east to Federal White Cement.

Efrain fought panic in the half-light at the bottom of his dusty prison. He tried to wiggle his toes and was relieved when they responded.

He thought of his native Colombia, where he had owned a grocery shop. When he became involved in politics in that violence-torn country, his shop was shot up and his brother, Salvador, was kidnapped, never to be found. Knowing he could be next, in 2001 Efrain packed up his son, wife and 12-year-old daughter and fled to the US.

2 years later they moved to Canada and were still awaiting the results of their refugee hearing. God, he thought, you did not bring me this far to die here.

The rescue begins
When London's technical rescue squad arrived at the silo, firefighters from 4 departments and an air ambulance were already standing by. Black took one look at the menacing ledge of hardened concrete hanging over the victim and estimated it weighed 15 tons. Knowing the cement cake was unstable and could tumble at any time, he ordered all conveyors and augers operating within 100m shut off; one of the biggest fears in silo rescues is vibration that can cause material to shift and collapse.

The rescue crew set up their own tripod and rope system directly above Efrain. Firefighter Dan Glanville would descend into the silo to size up the situation. Stepping into his full body harness and slipping on a breathing apparatus, he was slowly lowered, careful to ease himself around the protruding ledge.

Equipped with a micro-phone and earpiece that let him speak hands-free, he reported to his chief as he went: "The ledge is about 2,5m thick and is hanging about 2m above the victim." He didn't need to say that if it sheared off, it would fall directly on him and Efrain.

Some 18m down, Efrain was wedged at the bottom of a trench more than 2m deep and barely half a metre wide. His face was just centimetres from the wall, and the material around him was hard packed. But the slope leading into the trench, on which the men had been working, was littered with unstable rubble, from beach-ball-size rocks to fine powder.

Remaining suspended, Glanville touched nothing. He bent over to pat Efrain on the head. "Take it easy," he said, and the victim gave him a thumbs-up signal. Glanville secured a rope to Efrain's harness, reinforcing the frayed steel cable so he wouldn't slide deeper into the dust.

I n 20 years as a specialised firefighter, Black had done rescues from trenches, in confined spaces and with ropes, but he had never encountered an incident requiring all three techniques. The team knew that a man buried even to his knees could not be pulled out; his legs would be torn off.

They would have to shore up the walls around Efrain to keep them from collapsing, then – while dangling in mid-air – dig him out. The level of difficulty was far greater than Black had first imagined.

Shoring up the walls would involve going deep into the trench, an extremely treacherous place to work. As chief, he would normally supervise the proceedings, but he couldn't bring himself to place his men in such danger.

"I'm going down there"
Black called over his colleague, Capt. Ken Gaskin. "I'm transferring command to you," he said. "I'm going down there."

Black asked the Embro volunteer firefighters to cut sheets of 2cm plywood to be brought in through the narrow entry portals. He also ordered the bottom cut out of a 170-litre plastic rubbish bin to be squeezed down the hole.

Evening turned to night. Embro firefighters set up lighting through a small inspection hole in the roof as a fire truck ferried materials up to the silo roof on its 26m aerial platform.

Efrain's surge of hope at having contact with Glanville evaporated as the hours passed. "What are they doing? Why aren't they pulling me out?" he asked his son.
"They are going slowly so that they do it properly," Efrain, Jr, replied.

Efrain was becoming hoarse from shouting up to his son and was afraid losing his voice would further isolate him. He felt himself drifting into hallucinations, imagining he was falling, but he forced himself to be calm. Please, Lord, don't let my son have to watch me die! he prayed.

At 9.30pm Black was lowered into the trench, directly behind Efrain. He ordered the plastic rubbish bin be sent down, and he slid the "tube" over Efrain's head and arms to protect him from falling debris. Three sheets of plywood 2,5m long and 60cm wide were also lowered. Hanging in his harness, Black hammered a crossbar to the plywood to form a makeshift wall. When the banging sent showers of rubble tumbling down, Black covered the top of the rubbish bin with his body to shield Efrain.

Working while suspended in mid-air was very tiring, and Black was soon drenched in sweat. Before heading up after one and a half hours, he grabbed the victim's hand and felt him squeeze back. God, he thought, don't let me be the last human contact this man has. Black reached the top of the silo at 11pm. Efrain had been trapped for more than 8 hours.

An industrial vacuum truck had arrived and its 15cm -wide hose would be used to suck out the rubble from around Efrain. Shortly after midnight, firefighter Ben Ladouceur was lowered into the silo, positioning himself behind the victim. Using a sharp pike pole strapped to the end of the vacuum hose, he broke up the hard material and sucked up the rubble, but the chunks repeatedly clogged the hose. When Ladouceur returned to the top an hour later, little progress had been made.

Black was stumped. How could the material around Efrain be so hard? Searching for other options, the team considered boring up from beneath, cutting into the side of the metal silo to reach Efrain, and even calling in a rescue team from Toronto that specialised in collapsed building rescues, but too much time would be lost. Then Black had an idea.

"I think we've found the channel."
"Ask your father in which direction his legs are pointing," he told the son. Efrain responded that his legs were bent at a right angle in front of him; he had been dragged into the hole at an angle by a channel of dust.

"I think we should try vacuuming in front of him," Black suggested.

I t was 1.12am when a fourth firefighter, Brent Kirchner, was lowered into the silo. Suspended above Efrain, he shoved the vacuum hose into the narrow space between the rubbish bin and the trench wall. He was surprised when the ground yielded soft dust.

"Captain," he reported, "I think we've found the channel."
As Kirchner worked, David Vusich, a paramedic, warned Black of another pressing danger. "As soon as you get the pressure off his legs and the blood starts returning to his system, you could lose him," he said. Efrain, who had now been trapped for 12 hours, could become a victim of "crush injury". Extreme pressure on extremities can slow blood circulation, allowing toxins to build up in the tissue. Suddenly releasing the pressure could flush the toxins into the bloodstream and cause cardiac arrest and death within moments.

Knowing they had to move quickly, firefighter Darrell Black (no relation to Mike) suited up and continued the effort to suck rubble from around Efrain. When Efrain complained of pressure on his right knee, Darrell directed the hose to that spot and uncovered the handle of a shovel pinning him down. "Give me another 40 seconds of suction and I've got him!" Darrell said, working as quickly as he could.

"I think he's free"
It took many long minutes of stopping and unplugging the hose before he got his 40 seconds of suction, but finally he removed the shovel. "I think he's free," he radioed.

Once the slack in Efrain's rope was taken up, Mike Black gave the order: "Haul!" Efrain's legs felt as if they were breaking, but he kept silent. Feeling the resistance on the rope, the firefighters then released the tension. "Do you feel any pain?" he was asked.

"No!" Efrain lied. "Keep pulling. I'm coming out." Black watched as Efrain popped from the trench like a cork from a bottle, kicking his legs free. They raised him slowly until he had cleared the ledge, then sped him to the roof. Cloaked in white dust, he reached the top at 4.06am. Paramedic Vusich was astounded at how healthy he looked. . "It's amazing," he said, "that he suffered no major injuries."

"Thank you! Thank you!" Efrain repeated, drinking in the air of the open space as he was loaded onto a stretcher and lowered to the ground