There are two key phrases in this article "intermodulation distortion" and "when signal processing equipment behaves in a nonlinear way". While there is not a

There are two key phrases in this article "intermodulation distortion" and "when signal processing equipment behaves in a nonlinear way". While there is not a concrete description of the signals that might have been present in the building, I completely understand how these non-linearities can cause havoc. I previously spent almost 30 years in the cable television industry and the transmission of broadband signals requires linear amplification over almost three magnitudes. The two main distortions we worry about are Composite Second Order and Composite Triple Beat. This distortion represents all the permutations of sums and differences of two and three signals respectively. In narrow band communications, we amplify the signal and then filter out everything except the desired signal. In wide-band electronics, these products of distortion will often fall on top of other signals you're sending. The only way to succeed is to create very, very linear amplifiers (usually by burning a huge amount of bias current relative to the signal power).