Mt. Nyiragongo, Democratic Republic of Congo
Equipped with giant lava lakes, this thing looks like the kind of volcanoes you see in movies. There is always a constant worry, though, that the crater walls might give in and the massive lava lake will drain onto the surrounding communities. This has happened before, and will likely happen again.
*heck
More like 14 million!
1.6 million people in 1951.