By Andy Gallacher BBC reporter in Nacogdoches Texas

I arrived here in Nacogdoches just hours after debris from Columbia began showering down on this small community.

But my first view of the scale of this catastrophe came from the flight into Fort Worth, Dallas.

As we approached landing, the pilot came over the speakers and told passengers to look out of the windows.

Huge chunks of the Columbia were clearly visible smouldering like forest fires as far as the eye could see. It was an awe-inspiring sight and one that gives you some idea of the scale of this tragedy.

Dr James Kroll from the National Forest Institute says Nasa will never find all the pieces of the craft.

"Thousands of people have been calling in to the control centre. Its my prediction that 10 years from now people will be walking in the woods here and finding pieces of Columbia," he said.

Children 'playing with debris'

Here in the small community of Nacogdoches the impact has been felt more than anywhere else.

I was the first BBC reporter on the scene on Saturday and the debris from Columbia was scattered throughout the streets and houses here.

The largest piece - what looked like a sheet of corrugated iron surrounded by pieces of Styrofoam - landed in the middle of the town square.

Adie Massaria, a student, said: "It sounded like a big boom. It rattled the windows for about five seconds and I didn't know what was going on."

The community has been shocked by the shuttle disaster

She told me that just after debris hit, she saw children playing with pieces of the craft in the street.

The town square has become the focus for this tragedy now, and people have been arriving from all over the state of Texas.

Some have laid flowers in the square, others leaving notes expressing their grief for the loss of seven lives.

Everyone I have spoken to has told me that nothing ever happens in Nacogdoches, but despite that the community has reacted with typical Texan toughness.

Just about everyone has downed tools and joined volunteer search parties in an attempt to track down and mark as much of the debris as possible.

I followed one party to a nearby school that had been badly hit by the wreckage and found first hand how easy it is to find debris.

Traumatic search

The school playing field is scattered with wreckage, from charred pieces of metal the size of a finger nail, to large chunks of computer circuit board and fuselage.

But for some volunteers the searches have proved more traumatic.

The children of two farmers found the remains of one crew member and close by one man found a helmet and uniform badge bearing the names of all seven astronauts.

Duke Lyons, the city manager in St Augustine, Texas, told me that human remains had been found.

"We bless them and bring them back to the morgue," he said.

As each day passes more and more volunteers are arriving in eastern Texas to help in the searches.

Community centres and churches have been turned into temporary control headquarters, but it's not known when Nasa will stop their search for clues.

This tightly-knit community has been hit hard by this tragedy. America worships its astronauts and is proud of the space shuttle programme.

It will take years for the people here in Nacogdoches to recover from this disaster but for now they are just getting on with the job of doing all they can to help.