Quote from the article:
"Heap said the garbled transmission could indicate that electrical failure caused the crash. The National Transportation Safety Board and the Federal Aviation Administration will investigate the cause of the crash."
No, there was no "apparent electrical failure", but there was an opinion that an electrical failure was possible. The quoted person is not a pilot, but the airport manager.
Consider the airplane - what other electrical equipment might be installed than the transponder and radios, none of which were required or even existed in the original models back in WWI.
Everyone - anytime something like this happens, can we please NOT jump to conclusions within hours of the event? If we're so damn smart and know the reasons, why aren't we working for the NTSB and not taking a year or so to make a determination?