Demo bathroom-plumbing under slab

[Backwoods]

I'm in the process of demoing a 1/2 bath where I will be useing instead for a hallway. The sink plumbing is right in the middle of where I will be installing the door to new hallway. My problem is I need to capp off 1/2" galvanized pipe under the slab but keep water flowing to another bathroom beyond. My question is, is there a compression fitting that can be used and be dependable or does it need to be threaded. The line is running directly beneath a bearing wall so i didn't want to jackhammer back to main supply line. I have no threading tool. Any help would be appreciated. Thanks

[johnjh2o]

If it is galvanized pipe there should be a fitting below the slab either a tee or elbow. Just remove the nipple and plug the fitting. Your dealing with old pipe so be sure you use two wrenches when removing the nipple and installing the plug. Excessive movement could cause damage to the line that will still be in service.

John