Why would my coworker (39yo male) all of a sudden begin ignoring me, going as far as to disregard work related emails?

Anonymous

When I first started with the office, my coworker and I would talk on the phone daily. We would Snap on occasion, consult with each other on work related issues, and generally vent to each other. Over the past month he started to become a little more distant but was still responsive until two weeks ago. At that point he has completely stopped responding to any method of communication. He has not answered work related to emails, or any of my attempts to reach out to determine what happened to cause the relationship to turn south. I’m at a loss as I feel like I lost a reliable friend and I cannot figure out what would have caused the deterioration.

Updates
6 mo
There have not been any disagreements or arguments between us. We’ve always been very agreeable and professional, even had inside jokes. We are both married as well if that makes a difference. I have tried reaching out to figure out what happened because it has been so sudden and abrupt but I have received no response.
Why would my coworker (39yo male) all of a sudden begin ignoring me, going as far as to disregard work related emails?
4 Opinion