Steam Deck screen shut off then it randomly started emitting a horrific noise??

I was just playing my Steam Deck on silent with the charger plugged in when the screen suddenly went black. I thought it died, which fine, sometimes the charger can’t keep up with the game. But then it started screeching. It was louder than even my fire alarm. I couldn’t hear my tv. The power wouldn’t shut it off, I tried unplugging it, I tried turning the volume down, but like. It was just off and absolutely screaming bloody murder. The sound was somewhere between a high pitch almost whistle tone and a lower pitch scratching sound. I ended up having to cover it in blankets to mute the sound where it finally stopped. I haven’t turned it back on since. I was too panicked in the moment to take a video unfortunately. Has this happened to anyone else before? What the heck??