Del Walsh was a paramedic working for the Nuka-Cola Corporation at Nuka-World before the Great War.
Background
He was dissatisfied with the safety regime at Nuka-World and recorded a report to be sent to John-Caleb Bradberton directly after supervisors ignored his concerns.
It's unknown whether Mr. Bradberton ever received the holotape as the report is found still on the reception desk in the infirmary.
Appearances
Del Walsh is mentioned only in the Fallout 4 add-on Nuka-World.