A family member is involved in an accident, but it is covered up. A few years later, the man who now runs an escort club is again involved in a mysterious incident.

I will add this; you should personalize the logline and add a goal, because 'family member' is very vague.

"When his 'sister' <-- (Brother, cousins, something specific) is involved in a terrible accident, A club owner 'must discover' <-- (Goal) if someone is targeting him and those he loves."

Make us feel the loss.

May I suggest you read the training materials on this site? This is not a story concept as it merely lists two events.

Read the sections labeled "Formula" and "Examples", then read some example loglines here on the site and learn from the reviews.

Good luck!