On September 11th 2001 terrorism struck at the heart of global business.

The human cost has been immense. Thousands are dead. Their families, friends and colleagues are grieving.

The Money Programme follows the hardest hit firm Cantor Fitzgerald as survivors struggle to cope with the disaster. And we follow the economic shockwaves through the week as they hit airlines, insurance and hotels and move on to affect us all.

For the fear now is that this ruthless atrocity will push the global economy - already teetering on the brink of recession - over the edge.

On the morning of September 11th, the working day was beginning at Cantor Fitzgerald - one of the world's biggest brokers of shares and government bonds. Their offices were at the very top of one of the two twin towers of the World Trade Centre.

That morning, Cantor Fitzgerald Chairman Howard Luttnick was late into work. He'd taken his son to his first day at school.

His brother was already in the office along with hundreds of other Cantor employees. When the plane hit, 700 staff were trapped in the burning tower.

He was stuck in a corner office, there was no way out... he was not going to make it

Howard Luttnick, Chairman, Cantor Fitzgerald

"He called my sister just after the plane hit and he told me that the smoke was pouring in . He was stuck in a corner office, there was no way out and he was not good. He was not going to make it."

With the heart of America's business and financial community ablaze, tens of thousands of employees from some of the world's biggest banks, insurance companies and brokers along with an army of service staff struggled to escape.

Meanwhile in Cantor Fitzgerald's London offices President and CEO Lee Amaitis was watching the horror unfold live on television:" I was rounding my guys up to find out exactly what we were supposed to be doing, of course I'm watching the news at the same time."

Lee Amaitis "I know everybody in those buildings, I know all those people"

As the building collapsed he struggled to cope: "I mean how, how can you possibly imagine that that's going to happen, and then the other building collapses...I know everybody in those buildings, I know all those people, I hired a lot of those people. A lot of those people worked for me because I hired people that worked for me... just great people."

As the desperate search for survivors continues, Cantor Fitzgerald's remaining staff are insisting they want to get back to work.

The economic shock waves of terrorism are already spreading further. The airline industry is losing hundreds of millions of dollars a day.

The World's Biggest Claims

1988: Piper Alpha disaster - $2.8bn 1994: Los Angeles earthquake - $16bn Hurricane Andrew - $20bn

In the city of London they're trying to work out another of the major costs of the attack on the WTC. - an insurance bill so high it will shake the industry and increase the premiums we all pay.

This has also plunged the airline industry into dire straits. New reservations collapse by 30 percent. BA calls crisis meetings and Virgin grounds five of its jumbos and slashes 1200 jobs.

Airline industry is in crisis

US airlines are even worse off. Continental has already announced 12,000redundancies, and the company predicts 100,000 for the industry as a whole. Observers say most US airlines will be bust by Christmas.

Whatever happens, it looks as if the collapse in passenger confidence and ticket sales could last for years. Images of planes as weapons of terror will be hard to erase from the public mind..

To try to maintain confidence, there are emergency interest rate cuts round the world. But there's another danger: the oil price. Immediately after last Tuesday's disaster the price jumped but came back down after a pledge from OPEC countries to guarantee supplies. But with President Bush making increasingly bellicose statements about retaliation that could change.

Some observers are worried that American retaliation could ultimately affect the supply of oil. History shows that conflict in the middle east usually leads to higher oil prices.

We know from modern history that every time there's a very sharp rise in the price of oil the world a year or two later goes into recession

Professor Andrew Oswald, Warwick University

As Professor Andrew Oswald says: "World prosperity depends crucially on cheap energy, and we know from modern history that every time there's a very sharp rise in the price of oil the world a year or two later goes into recession. If the current tension puts a lot of upward pressure on the barrel price of oil then the world economy will go into a very severe downturn."

For the economies of the West riding out the coming uncertainty won't be easy.

For those worst hit by last week's tragedy determination may be the best way to cope with grief.

While New Yorkers attempt to come to terms with the immensity of their loss, political tension round the world is growing and prospects for the global economy look increasingly precarious