Minecraft wiki entry for Mining, associated text: Be careful when digging out any blocks beside the player. Lateral breaches into lava pools or monster caves can be hazardous. Be ready to plug the hole, or hop up and throw blocks down so the player can escape upwards. Also, be sure that the 3×2 section hasn't opened into a cavern before players hop down. Keep the pit well-lit. When players reach the bedrock level, make a 3-deep pit on the descent side. Fill in the middle and ascent sides as needed, as in the screenshot.