Why did my iPhone call 911 by itself?

So , I’m asleep, phone lying on table next to me, connected to charger. At 255 am it called 911. I had EarPod in so was awakened by ringing. Got up picked up phone, black screen. I push and hold on and volume buttons. Nothing. I get up and change out charger, phone comes on, I go to recent calls and see it’s called 911 and they called back, then it called 911 twice after, I assume that was me trying to turn it on. So I call 911 and tell them I’m fine. Now it’s 305. Weird huh?

[Re-Titled by Moderator]