Loud humming/whirring sound early mornings
Anyone else occasionally hear a pretty loud humming or whirring sound in the early morning hours (~5am)? I live near 136th and Lowell and occasionally I wake up early and hear what sounds like pretty loud machinery in the distance that goes on for quite while, gradually fading out over an hour or more. If it were a lower pitch I would think street cleaning but I don't think it's that. Anyone know what this is? If not I'll call the city today and see what I can find out.