LEIGH SALES, PRESENTER: This is the extraordinary story of the ambulance crews on the front line in the battle against Ebola.

While First World countries like Australia argue over whether to send assistance, medics at ground zero in Liberia confront an overwhelming task as they try to contain the outbreak.

In the capital Monrovia, a city of more than a million people, there are just 15 emergency crews assigned to the job.

As the World Bank warns that the battle against Ebola is being lost, New York Times reporter Ben Solomon spent three weeks with the ambulance workers risking their lives to save others.

GORDON KAMARA, AMBULANCE WORKER: My name is Gordon Kamara. I'm an ambulance (inaudible). From March up till now, I've been fighting these Ebola cases. Our job is to save the people.

ON-SCREEN WRITTEN FACT: More than 4,000 Ebola cases have been reported in Liberia. More than 2,300 have died. In a city of around 1.5 million, roughly 15 ambulance teams fight the outbreak street by street.

GORDON KAMARA: In the morning, we start very fresh. Today is going to be a very busy day. Getting - detecting cases from Westpoint. I have assessed cases in Johnsonville. Another five cases in Benton. Three cases in Kaba. The calls just keep coming, the call just keep coming. ...

... There are patients all over. The first thing I do, I give them courage. I tell them, "Don't be afraid." They feel fear. I see it in their eyes. I'm tired of seeing people getting sick. I don't rest. Even when I go to bed. Sometimes I see them in my dreams. ...

... I live by myself. This is my boy. This is his birthday. He's four years. My family are so close and they are also far. They are close to me when I come and look at the photos and make them close to me, but physically, they are far from me. I don't see them.

ON-SCREEN WRITTEN FACT: Since the outbreak began, Gordon moved his fianc and six children to a separate house to protect them from getting the virus.

GORDON KAMARA: Because of the condition, I accept it. This is how it's supposed to be. I just look at the photos and imagine them. I have been lonely throughout. More than five months, my family doesn't come around.

WOMAN: Open, I am ill. Open, I am ill.

GORDON KAMARA: We have only three treatment centres in Monrovia. It is insufficient.

ON-SCREEN WRITTEN FACT: Gordon's uncle has been admitted to the hospital, the first in his family stricken with Ebola. The nurses deny him entry to help.

GORDON KAMARA: He is here. But nobody knows who is dead and who is alive in here. I feel hopeless. ...

... Sometimes when I sit down and think about it, I think, "Wow, that could be me."...

... Any little mistake you make, you're going to be down with the virus. ...

... Every morning, I pray. I pray that one day Ebola will go. ...

ON-SCREEN WRITTEN FACT: At shift's end, Gordon brings his final patient of the day to a treatment centre. All the beds are full.

GORDON KAMARA: There is no space. The doctor, he can't take the people because he's supposed to admit 50 persons, and now he got 85 in there. He's overloaded. ...

... She's very critical. She's vomiting. She's weak. If she doesn't go in, she won't live. ...

... There is no hope here. ...

ON-SCREEN WRITTEN FACT: Turned away from treatment centres, Gordon must return her home.

GORDON KAMARA: Ebola will last for long. In the next three to four months, the Ebola will be worse. I wish I could do more, but it's not easy. We try. We try our best, but ... We cannot do more than what we can do.

ON-SCREEN WRITTEN FACT: The 17-year-old girl died at home the next day.

LEIGH SALES: That report by Ben Solomon.