It was just before six on Tuesday afternoon when the rescue service in Beirut was told by the police that a thick smoke was over the city port.

First Lieutenant Raymond Farah, who took the call, tells Al Jazeera that at first it was unclear what caused the fire. He refused to send staff to the scene before he knew.

After a while, a security official called and told them that the fire was loose in a hangar with fireworks.

A team of nine firefighters and a nurse were dispatched to the scene. They kept in close contact with Raymond Farah by telephone.

"Something is wrong"

Once in place at the fire-ravaged area, the fire truck and ambulance were let in through a gate by soldiers who were on duty.

According to the team, something was not right.

- Something is wrong. It's a big fire and we hear a crazy sound, they told Raymond Farah and asked for reinforcements.

Raymond Farah and a few others at the station began to get ready to go out and assist their colleagues.

"No fire truck, no ambulance"

Once down by the fire trucks, they were hit by the huge explosion. The whole city was affected. 158 people have been found dead and 6,000 people have been injured.

Despite the chaos in the city, Raymond Farah managed to get down to the port where his deployed team was located.

But he could not find them.

- When I arrived at the hangar, there was no fire truck, no ambulance. It was as if they had gone up in smoke. The largest piece we have found of them is no bigger than a hand, says Raymond Farah.

One person from the team, the nurse, has been pronounced dead. The rest have still disappeared without a trace.

According to Brigadier General Najib Khankarli, chief of Beirut's rescue service, there was no idea that the burning hangar contained 2,750 tonnes of ammonium nitrate, a highly explosive substance, before the incident.

- If we had known, we would have acted completely differently. We had evacuated the area and had absolutely not sent these young men and women to the scene, Najib Khankarli told Al Jazeera.