Now we knew why the military was trying to evacuate North Sydney. I knew why Doctor Hunter had such a worried look on his face earlier, why he kept checking his watch every thirty seconds.

According to the voice on the other end of Kenji’s radio, there was an entire horde coming this way. An endless stream of people who were infected with the Oz virus. The horde stretched as far as the road stretched, as far as they could see. I couldn’t even comprehend what I was hearing. I tried to imagine all those infected people, each as violent and aggressive as the next, biting and eating their way through everyone crammed on to the highway. But I couldn’t. The thought was too gruesome.

“What was that order?” Kim asked.

“They’re going to blow up the bridge,” Kenji said in disbelief.

“What?” Maria shrieked. “While we’re still on it?”

“Are they going to use nukes?” Kim asked.

“I don’t know,” Kenji said as he looked around for a way off the bridge.

The crowd started shouting and the gunfire in the distance intensified. We could see the jets now. They flew in low and fast. They were so low you could see each individual missile on the underside of their wings and see every little scuff mark. The noise of their engines made you feel like the world was coming to an end.

Seemingly from nowhere, a whole swarm of helicopters descended and hovered over the bridge, dropping rope ladders to extract the soldiers. A few people tried to climb up but they were quickly beaten back. The soldiers left the majority of their equipment behind. They took with them only what they could carry.

Once the helicopters cleared out, we could see the jets way off on the horizon begin to slowly turn back around.

“Run!” Kenji shouted over all the noise. “Go! Run as fast as you can.”

We started running, as did everyone else. No one really knew where they were running to. We could only move in one direction. We could worry about what was on the other side when we got there. The only thing we knew for certain was that we needed to get off the bridge. It was a no man’s land. At that moment we were completely stranded above water and completely vulnerable.

We got about half way when we heard the first explosion. It wasn’t as loud as I thought it would be. The bridge shook and groaned. Everyone ducked instinctively. But nothing seemed to happen. The collective panic that had gripped everyone disappeared momentarily and was replaced by confusion. The screaming and shouting was reduced to a murmur.

On Kenji’s radio we could hear loud and clear the result of what had just happened. “Positive ignition for southern end of tunnel. Repeat, positive ignition.”

This voice was different to the other one. It was calm, almost emotionless.

Kenji yelled at us to keep running. So we did. People all around us started to catch on. The panic returned and so did the screams.

“They’ve blown the southern entrance to the tunnel!” Kenji shouted.

I couldn’t believe they actually did it. How many people had just been killed? How long before they blew the bridge?

We didn’t have to wait long for an answer. About ten seconds later, a huge explosion erupted at the northern end, right where we were standing not even five minutes ago. Everyone on the bridge was knocked off their feet. The whole bridge started to sway and the massive steel support structures began to buckle and warp out of shape.

The road eventually broke away from the northern pylon and crashed into the water. As the road fell away we started to slide downwards, to a certain death. I’m not sure how far it was, but it felt like we were falling forever. I’m not even sure how we survived the initial impact but the next thing I knew, we were in the water with thousands of other people.

I came up for air. Jack and Maria were right next to me. They were good swimmers, both of them. Jack was probably one of the best swimmers at school. He grabbed me because he knew I was terrible. Sure I was getting better with all those surfing lessons but I was still an amateur compared to those two. And right now was no time for doggy paddle.

Some people were being crushed by falling debris and falling people. Others were unconscious by the time they hit the water. But the thing that scared me the most was not the falling bits of concrete and steel, it was the people who were dragging others down underneath the water, drowning them without realizing what they were doing. They weren’t doing it on purpose. They were just trying to survive. They were just afraid. So I was thankful that Jack had grabbed me. If he hadn’t, I probably would’ve been one of those people, dragging someone else down with me.

We managed to swim a few meters away from where we hit the water. Any second now they would blow the remaining charges on the bridge and the whole thing would come crashing down on top of us. I wiped some water out of my eyes and looked up. The parts of the bridge that had survived the initial explosion were straining and twisting under the enormous stress. The noise of breaking steel was terrifying. It reminded me of Godzilla’s roar; metallic and blood curdling. Somehow the road was still attached to the southern pylon. And amazingly, there were a lot of people still actually on the bridge, holding on for dear life.

Everyone else had fallen into the water with us. There must have been thousands of people. We looked around for Kim and Kenji. They weren’t too far away. Kenji was telling us to go, to swim as fast as we could. So we did. We swam hard. It was simple really; we needed to get as far out of the way as possible, because when the bridge came down, it would kill everyone underneath.

I saw Maria swimming out in front of Jack and me. She had already caught up to Kim and Kenji. Jack was pulling me along. There were people all around us. Splashing their arms wildly, pumping their legs as fast as they could. Jack got kicked in the face a couple of times.

Above us, the bridge continued to slowly break apart, but it seemed to be holding for the moment with the southern end still intact. We were able to put some distance between us and the rest of the crowd. Suddenly there was another explosion. Metal screamed and shrieked in pain as the iconic bridge buckled and finally collapsed into the harbor, crushing anyone trapped beneath it.

I looked back and saw a huge wave of white wash bearing down on us.

Jack grabbed my hand. “Duck dive!” he shouted. “Just like I taught you, remember?”

I nodded my head as I remembered the very first time he tried to teach me how to surf. Lesson number one; diving under a wave to avoid getting killed. I think I swallowed my weight in sea water that day.

He gripped my hand tighter as I took a huge gulp of air. “Wait for it! OK, now!”

We dove together, the white water crashing all around us, pushing us around like we were in a giant washing machine.

We resurfaced and I took another deep breath. The water was still churning as the road and the massive steel supports sunk to the bottom of the harbor. There was now a huge expanse where the famous bridge used to be.