My home was build in 2006 and I moved in in 2015. I haven't had any electrical issues until the last 6 months. First I noticed the lights would periodically dim in one room. About 2 months ago, I lost all power to the same room where the lights were dimming. I replaced the circuit breaker (which hadn't tripped). A couple weeks later the power for this one room would periodically go out when I turned the lights or tv on, then would eventually come back on. Once again, the breaker did not trip. Finally had an electrician come and look at it is he said that the must have been a loose connection which has caused it to arc, resulting in irreparable damage to the buss bar and panel. Some of the neighboring breakers are now fused to the buss bar. What could have caused a connection to become loose? Is this typical normal wear and tear? Is this discussed anywhere in NFPA? I did find in NFPA 70B Chapter 17.9 where it talks about routine maintenance to find loose connection, but nothing that explains the cause.