The ammo building on the first stage of trainyard for instance, and the closed white bridge on the second stage of bridge etc. If you’re standing hard up against a wall as a Kira laser touches it, you’ll die.
The same thing can be said for Stokers molotov. If a molotov is thrown inside a room or up against a wall and the glow of it is showing on the other side of the wall, you will die if you touch the glow as well.
Perfect example of this was the last stage of terminal, the MG that sits between the two final objectives. A guy on the enemy team threw a molotov at that MG, and it killed me when I was inside the objective closer to the attackers spawn because the flames partially appeared through the wall.