It's quite possible that the fleet is not insured.
When I worked with FlightSafety International (who had 108 aircraft, at the time) the "flight line" was not insured for anything other than third party - working on the assumption that the cost of insuring ALL the aircraft, rather than the cost of replacing any one of them (should it "come down"), was not a viable proposition.
Same, apparently, with the shopping chain Marks & Spencer - they were not, when I worked with them, insured for fire. The fire security was top notch and, again, the costs of rebuilding one store was less than insuring them all.
The whole thing of insurance is "risk assessment". Somebody has been asking themselves, "What's the chance of losing 50 of our 65 aircraft at once?".
As for ERAU - I dread to think how many staff (flight instructors, dispatchers, mechanics, refuellers, administrators - the list goes on) are now out of work.
I wonder how many "paid up front" students are suddenly without a course to complete and no funds to go elsewhere with.
A dreadful happening for the Florida flight training industry. The knock on effects will be far and wide - even just for instructor salaries.