Random unexplainable ringtone in middle of the night

My iphone just woke me up by playing a weird ringtone (I’ve never heard before) randomly at 2:05am this morning. This happened right before/as a helicopter could be heard going over my house - not sure if these two things are related, but if not then it’s a super odd coincidences. I’d never heard this ringtone before, and when I went to look at my phone to shut it off my phone screen was black and wouldn’t turn on / respond when pushing the side button. The ringtone stopped after a few seconds, and the phone started working. I checked to see my alarms and notifications, but nothing was out of the ordinary and nothing seemed to indicate a notification was triggered.

This is a head-scratcher and has me a little spooked / confused in the middle of the night. Wondering if anyone has encountered something similar. Also wondering if a helicopter going by could have played some role in this??