One example would be a New Berlin, New York case from 1964 where the occupants were performing repairs on a craft.
You can read about this case in the book UFOs Over New York By Preston Dennett.
To her surprise, she also found an apparent piece of cable. Says Hatzenbuhler, "The outer part of it looked like the wrapping, something like a brown paper towl, only it wasn't like our paper towl. It felt rather like that, and was dark brown in color. It seemed to be a wrapping for a cable, tubular. And in the center of it - it had been cut laterally - you could see the strip, maybe an inch wide, more or less, something that looked like finely shredded aluminum strips laid in there, and it was as long as the piece of paper, and that the color and feel of aluminum, although it wasn't aluminum. It didn't behave like aluminum. Aluminum will crumple and this didn't crumple. You couldn't crease it. It was inside, strips of this, laying inside the paper. You could remove the inside, for the outside paper had been cut along the length of the piece, but it was all together."
Unfortunately, this crucial piece of evidence has become lost.
What a crock. ETH'ers always play the cover up card, why do you feel this is necessary in todays society? For one, you could filme the thing and email it to a thousand sources at the touch of a button, Cover that up. Alternatively, all one need do is take photos to prove you were there first, and then make one phone call to the local radio station. Within 10 minutes there will be too many people to cover up the story at the site and media will have the evidence spread across the globe in seconds. Cover that up.
This is the digital age, the old excuses do not work anymore.