The town was flooded when the dam burst.
The town flooded when the dam burst.
I'm fairly counfused about the correct usage of the verb flood. I know that the verb form of the word has two similar meanings with reagrd to a natural disaster, first is "a state of overflow" and the second is "to become inundated or submerged caused by that overflow" (as it's noticable the second is what we exactly need to focus on). But they are both used in active voice as far as I'm concerned ,however, I also pretty often come across the way it's used in passive, so does it mean slightly different apart from these both when it's in passive?