MinecraftServer minecraftserver = MinecraftServer.getServer();
WorldServer worldserver = minecraftserver.worldServerForDimension(world.provider.dimensionId);
Entity passenger = cart.riddenByEntity;
if(passenger != null && !(passenger instanceof EntityPlayer)) {
worldserver.removeEntity(passenger);
passenger.isDead = true;
}
worldserver.removeEntity(cart);
cart.isDead = true;