I guess the word, and question serious? could be viewed like "Kill me now!"
There is the 5Ws why, why, why, why, why of root cause analysis.
I suggest the 5Hs of serious: How, How, How, How, How.
The 5H might be alot for some CEOs, and this would answer the how serious question.
In agreement with an earlier post, It is a question of a question of a question audit method.
I hope this might be more in line with a course of questioning.
It might be my only

, nope! I checked, I have another

for later.
I might ask, is everyone safe in your company? (how do you practice safety?, Is your safety only LEAN-safe*)
*LEAN-safe, would be part of LSS, and just enough. Not a great type of safe.
How safe? (safe enough? safe to standard? zero tolorance? just a few died?)
How do you know? (who told you? how often?)
How do they know? (what is their reasoning?)
How does the report prove this? (is this number biased or weighted to look good? how much? where?)
How is it validated? (is safety spoken, a faith, or a practice?)
I would like to hear the word safety/safely in the same sentence which describes a job each time.
It would be correct to ask if the employees all got a Merry safe Christmas wish from the CEO.
.
In the end the CEO is in charge, and just asking him what his course and strategy are is my best answer.
As in my earlier post. He is at the top, and all questions for him are answered in course and strategy.
.
By the way, Have a Safe Merry Christmas. (o: