it sounds like it might have come loose at the bonnet end.
olly has the right idea. find where the mechenism is at the bonnet and see if you can see where the cable is attched too. then poke it with a screwdriver...
if it feels like it usually does, pull the handle and hold it open then get someone to give to bonnet a push / pull motion...happened with mine when the latch was getting sticky, and that got it open so i could grease it all up.