My Lacie wont mount its

Question

My Lacie wont mount its a rugged 250 gig, Was working fine till it got un plugged before being ejected. now will not mount. I can see it in disk Utilities. try to repair but can't the report is :The underlying task reported failure on exit,Verify and Repair disk ?LaCie?Checking HFS Plus volume.Checking Extents Overflow file.Checking Catalog file.Invalid node structureVolume check failed.Error: The underlying task reported failure on exit1 HFS volume checked 1 volume could not be repaired because of an error