Probably lithium polymer but yeah:
https://m.youtube.com/watch?v=yD_Eal1_5NIMy RC aircraft group has a 55 gallon drum with salt water at our flying field. RC aircraft pretty much exclusively use lithium polymer packs, sometimes 2 the size of bricks in larger models / big helis. If a lipo starts smoking, you chuck it in the salt water and it shorts it out + cools it down. The reaction when they short internally (such as when they malfunction or get damaged e.g. When a heli crashes and smashes the pack -- they're not super rigid) is more thermite than dynamite, but it can still burn through things like flying tin can aircraft.
Here's what happens when you overcharge a few on purpose and beat them with a stick: https://m.youtube.com/watch?v=coX0SwubG4A
Typically there's quite a bit of warning in the form of smoke first. Not sure if the chemistry in the Samsung batteries but they're likely lithium polymer. There are tons of different chemistries though: http://batteryuniversity.com/learn/article/types_of_lithium_...