There are quite a few examples... and Mr Fybush can probably name 'em all... of stations off for years and years due to things like... property condemnations under eminent domain where a suitable alternative site can't be obtained or the permit process takes a long time and results in legal cases... or hurricane damage where the city of license virtually disappeared... and so on. The FCC will be understanding in many such cases.
I seem to recall that an upstate NY station on 560 would come on once a year to keep the license, and that ruse went on for a number of years.
Right what you are talking about is called an "emergency STA", and the FCC is very specific regarding the requirements to meet such a deal. (Tower collapses, disasters, etc.)
STA lengths can vary depending on the situation, and type of STA filed. They can go anywhere from 30 days to 180 days depending on the situation.
According to the STA filing (BLSTA-20120308ABH), DJRA has 180 days to resume broadcasting, and must broadcast prior to April 2, 2013, or the license will expire as a matter of law.
See for yourself. http://licensing.fcc.gov/cgi-bin/prod/cdbs/forms/prod/getimportletter_exh.cgi?import_letter_id=32941