I have a 2016 Honda HRV which stopped working while driving 40 mph on a major roadway. Dealership claiming not to know the problem

Question

I was driving when the accelerator pedal ceased working along with every other major component in my car. I had to coast into a nearby parking lot. The starter and oil lights simultaneously lit up on the dashboard while car was still moving. When I lightly tried the accelerator pedal, heard a short semi- grinding noise before everything went quiet. The dash lights, power windows, and radio still worked, but there was no noise coming from the starter or any signs it was engaging the engine. I had it towed to a Honda dealership that ran a computer diagnostic that I was told came up with nothing. Yesterday, they said their mechanics looked at it and nothing they did could get the engine to engage. I was literally told that no one at the dealership has come across this before. This answer astounds me and was wondering if anyone has had a similar experience or could point me in a direction to research as my car knowledge is basic. I would think a certified Honda mechanic would know to check things like fuses, the solenoid switch, loose connections, broken ground straps, etc... Any ideas would be appreciated. Thanks!