There have INDEED been deaths attributed to the Black Widow! Rare but definitly has happened. Like Invictus mentioned, it really depends on the person. If you are sensitive to things like bees and what not, I am sure you are more at risk.
On the other hand, my mother has been bitten by a Black Widow in the face. It got her in the middle of the forehead. She didn't feel all that great and had a nasty wound for some time. But she is also slightly allergic to bees. So it really depends.