Canceling snapshot removal process

Hello everybody

I just wanted to ask is it safe to cancel- delete all snapshot process ? I've made snapshot a while ago and now made mistake of deleting it when VM is still runing , after 6h its 12 %.  I really need to cancel this proces cause i cant have any downtime on that VM. The size of snapshot is 150 Gb , im using ESX 5.5 free

If there is no option to cancel this process ,can I shout down VM now, during that process ?

Thanks

Wojtek