Mr. Varga said these recurring systems problems led inspectors to check the wire bundles that run through the system.

Yet Just visible between some of the wire bundles was a dull black substance arranged in the shape of a ball.

"Maybe the wire bundles is a connecting link, and so we need to examine that," he said.

As the wire bundles burn, the sensors begin failing by the dozens.

This was no computer terminal or sophisticated electronic relay center; the circuits were the wire bundles themselves.

They had labeled each wire bundle with descriptions of where the wires led and what they did.

That's where wire bundles were cut that caused the electronics to fail.

The wire bundles are wrapped helically around the hose while also being alternately layered one over the other.

He picked up another wire bundle with alligator clips on the end.

And this other clip was on the wire bundles that led to the detonators.