Friend troubles!! HELP.

So my friend was saying mean things about my other friend and saying that she didn't want to be friends with her anymore and then acting like nothing was wrong until a week ago when she gave her the cold shoulder. My friend then asked me why she was being ignored and I explained in the nicest way possible that our other friend had been saying mean things about her and wanted to move on with her friendship. I told her because I didn't want her getting hurt but now my friend who was talking shit has been getting people to message me telling me to leave her alone and stop talking shit and she's been threatening me. Am I in the wrong? And how do I fix this? PLEASE HELP!