It is indeed! The Sicarii, the radical group which held the fortress (the First Roman-Jewish War had a LOT of splinter groups on the rebel side) committed mass suicide shortly before the fortress was breached. Though the end result is unlikely to have been much different than if they hadn't - the Romans were vicious at the best of times; after a long siege, it would have been a massacre anyway.

The Israeli military used to swear their oaths at Masada, until someone pointed out that "Religious radicals murder their countrymen and then commit suicide when confronted with actual opposition" was a bad look.

The very same. And siege lasted for a long time. Fortress has huge cisterns and complex systems for collecting and preserving water in the middle of nowhere.