It is a general consensus among researchers that many of Bible stories have had historical background, I was watching an extraordinary program on History channel the other day about Sodom and Gomorrah. It also mentioned Jericho. The question is no whether some of those things happened but whether they had miraculous origin. Geology of Palestine is quite extraordinary and many natural phenomenons can explain perceived miracles.
The most potent mix in a story is not when you completely invent an even but when you mix reality with fantasy where subsequent generations can not distinguish between the two so they merge into one.
But I'm always open minded if someone can prove it to me that those event however extraordinary were also of supernatural or extraterrestrial origin. So far no one succeeded ...