Fire

You've seen the stories suggesting that an meteor air-burst destroyed Tel el-Hammam, which might have been Sodom, as well as trashing Jericho--though less emphatically. The combination of shattering, intense heat, and traces of odd minerals does seem to suggest something not within the military technology of the age. Pottery doesn't melt very easily--but have a look at what confined heat can do. People do worry about fire damage in tunnels and how to avoid/repair damage.

Tunguska would have been unpleasant to be underneath too. "Recent estimates place Tunguska-sized events at about one every thousand years." Um. The statistics are low, but spotting 2 in 4000 years, subject to a) not happening over the ocean and b) happening where people would notice, suggests to me a rate at least 10 times higher.