Will Jimeno Speaking at My College, Need Help Formulating a Question

Will Jimeno, Port Authority Police officer, will be speaking about his experience of being one of the last individuals to be rescued from the WTC complex on Sept. 11th at my college on Oct. 2nd. I am interested in asking a question that relates to the ground level explosions prior to the collapse of Tower 2. Will Jimeno has made it perfectly clear that he witnessed these explosions. Here are a few sources:

"That's when we heard a humungous boom. I turned around from were we came and I could look out into the lobby of 2 and I just saw a humungous fireball I mean the size of my house."
"I looked out onto the street and saw a fireball the size of my house hit the pavement."

John McLoughlin who was also trapped with Jimeno mentioned witnessing explosions too.

"We heard a loud explosion coming from the area of Building 2 and at that point Building 2 was collapsing."
"We thought it was car bombs going off."

My dilemma is that this man still has beliefs rooted in the official story which is evident if you continue to watch the first set of videos. I would like to "probe" him regarding these explosions and fireballs but certainly don't want to offend him considering what he did trying to rescue people's lives and all. So either two things will play out. Jimeno will mention these explosions during his speech or he will just pass over them. Either way I would like to be prepared with a question relating to these explosions.

Let's assume first that Jimeno touches on the explosions during his speech. What questions could be asked to get him to expand on the explosions and their potential source? Essentially how could I word a question the indirectly leads Jimeno to a response relating to controlled demolition or planted explosives without offending him or his intelligence.

If he doesn't touch on the explosions how should I as a questioner bring them up without having him rehash what is already known regarding his views of the explosions?

Thanks if you can help and I will try to record this if it occurs.