Well... You can. Sleep deprivation is one hell of a drug. After ~23h on a plane without sleep, I slept through a fire alarm at a hotel. It's unlikely that both

Well... You can. Sleep deprivation is one hell of a drug. After ~23h on a plane without sleep, I slept through a fire alarm at a hotel. It's unlikely that both pilots and other staff would ignore it, but "no one can sleep to" threshold is not that low.