ATOBTTR

I’m sorry you had this experience while traveling but unless I’m missing something, just what was DL’s fault here? Your issue seems to be with TSA but that’s not under Delta’s control. DL is under no obligation to hold the plane for you even if your travel companion runs ahead to tell them you’re coming. Airlines have schedules to keep to and slots to keep and hundreds of other passengers to account for and delaying the plane waiting for another passenger may not be feasible due to down line impacts. Why your travel companion boarded the plane with your stuff but without you also there is also a mystery and something you need to discuss with them and is not DL’s fault.