Following Aaron Krill, here is another engineer joke:
It was decided to build a bridge between heaven and hell. Half of the bridge should be made from hell and another half from heaven and these two shall meet in the middle. People from hell worked hard for this, as if the bridge is finished they could also once a while visit the heaven (who wouldn't?).
Up to a point where the two parts of the bridge should be connected, there wasn't any structure or whatsoever from the heaven's side. It was just empty space. Even after waiting for some time, there seems no activity at all from heaven regarding this bridge thing.
A call was made from hell to heaven, asking for explanation on what had happenned. "Well", expressed a representative from heaven, "we don't have engineers."