Sudden noise of grinding (almost like chainsaw) appeared. Any ideas what this is?

Hello,

As I was using my Mac to browse the web, a sudden noise appeared like griding or like a small chainsaw trying to cut through metal or something. The noise seems to be coming from the middle/top right side of the keyboard of a MacBook Pro.

My MacBook Pro was purchased in Feb-2017 and it is the 15" Mid 2015

The weird thing is that when I lifted the MacBook, the noise seems to soften and then when I rotate it vertically the noise stopped. Once I placed it back flat on the desk the noise reappeared. This behaviour persisted for about 2 minutes or so and now seems to be gone but I am worried about what that could be?