A seamstress and a sewer fell down into a sewer line.

The word 'sewer' is used twice with different meanings
and sounds.

1 - say SOU-er.  It means a person who stitches, as
with needle and thread.

2 - say SU-er.  It means a drain for taking waste
water or storm water away.

Another way to say this is:

The seamstress and stitcher fell into the storm water
drainage system

or 

Two workers, one who sew seams and another who
stitched appliques, fell into the waste water drain.

07/11/2002