Td4 banging/rattling

Hi am new to here and would love some help/advice.
I have a TD4 52 plate and driving today i had a rattling noise coming from underneath sounded like it was at front. parked up couldnt see anything drove home no banging/rattling.
Gone back out no noise but slowing down to a junction a huge bang, sounded like something fell off - nothing did and again no noise and cant see anything hanging lose ect.. the noise was too loud for nothing to be wrong any ideas anyone?
Thanks in advance

Hi I had a corsa years ago and similar thing happened,massive bang it sounded like a rock had been dropped on the roof!it was the shocker or spring not sure of correct word,anyway this had snapped

Hi thanks am getting it checked out soon as the noise was not good but drivin ok, thanks again