summon FallingSand ~ ~1 ~ {Block:stone,Time:1,Passengers:[{id:FallingSand,Block:redstone_block,Time:1,Passengers:[{id:FallingSand,Block:activator_rail,Time:1,Passengers:[{id:MinecartCommandBlock,Command:gamerule commandBlockOutput false},{id:MinecartCommandBlock,Command:fill ~2 ~-3 ~-1 ~4 ~-1 ~1 stained_hardened_clay 11 hollow},{id:MinecartCommandBlock,Command:fill ~2 ~-2 ~-1 ~4 ~-2 ~1 stained_glass 9 0 stained_hardened_clay},{id:MinecartCommandBlock,Command:"tellraw @a {\"color\":\"red\",\"text\":\"I'm only going to say this once!\"}"},{id:MinecartCommandBlock,Command:fill ~3 ~-2 ~ ~3 ~-2 ~ chain_command_block 5},{id:MinecartCommandBlock,Command:setblock ~3 ~-2 ~ repeating_command_block 5},{id:MinecartCommandBlock,Command:blockdata ~3 ~-2 ~ {auto:1,Command:say 1}},{id:MinecartCommandBlock,Command:setblock ~ ~ ~1 command_block 0 0 {Command:fill ~ ~-3 ~-1 ~ ~ ~ air}},{id:MinecartCommandBlock,Command:setblock ~ ~-1 ~1 redstone_block},{id:MinecartCommandBlock,Command:kill @e[type=MinecartCommandBlock,r=1]}]}]}]}