G'Day Ken.
Interesting observation you've made I hope you find out what it was.
Back in 1989 (sooo last century!) I was observing by myself from Falls Hill over looking town. I had my head down in some star charts when the area lit up. I thought a car had driven up behind me, then realised I didn't hear a car! I looked up and the whole town was lit up by a blue light not quite as bright as day (so it was probably fairly dim in all honesty as my eyes were dark adapted). The light was coming from a big fireball streaking over town towards me from the east. It broke in two and then into smaller bits which then burned up orange. But like you it was the sizzling noise that really made my hair stand up on end! That impressed me - it must've been so close! No sonic boom though.
For a long time I couldn't find anyone who had noticed this event, until last year. They remembered it as vividly as I did!
Al.