Later the problem was reported as 'Structural failure in the air'.

The cause was more likely to have been a bomb than a structural failure.

The accident appeared to have been caused by a structural failure, officials said.

"Clearly, there was some sort of structural failure," he said.

There was no evidence of mechanical or structural failure prior to the impact.

It might have been caused by a structural failure of some kind.

Instead, Government officials said yesterday that structural failure has become a prime focus of their inquiry.

It is not a good procedure for roads with structural failures.

A contemporary photograph and an illustration still exist which show total structural failure.

Eventually the crack grew large enough to cause structural failure of the disk.