Participating in a conference with company and NASA officials, Boisjoly and others warned Morton Thiokol and NASA not to launch the shuttle on the 28th. Later, testifying about the conference before Congress, Boisjoly said:

I...grabbed the photographic evidence showing the hot gas blow-by comparisons from previous flights and placed it on the table in view of the managers and somewhat angered, admonished them to look at the photos and not ignore what they were telling us; namely, that low temperature indeed caused significantly more hot gas blow-by to occur in the joints. I received cold stares...with looks as if to say, 'Go away and don't bother us with the facts.' No one in management wanted to discuss the facts; they just would not respond verbally to...me. I felt totally helpless at that moment and that further argument was fruitless, so I, too, stopped pressing my case.

Giving a speech about his efforts to delay Challenger's launch, Boisjoly tells what he did after the conference call.

I wrote the following entry in my notebook after returning to my office. "I sincerely hope that this launch does not result in a catastrophe."