Issue #20 was pre civil war and will be my base line.
When the Civil War tag went on the comic book, starting with issue #22, we saw a 50% increase over issues #21 and #22. This new number stayed about the same until the "death of" issue.
Issue #25 was the "death of" issue and it sold 100% over the Cap. Civil War issue numbers (#22-24), and 200% over the sales base Captain America had pre Civil War (#20-21)
Issue #26 saw a 27% decrease in sales from what we'd sold of issue #25, but was still 115% over the pre Civil War issues (#20-21), but only 50% more than the Civil War crossover issues (#22-24).
With issue #27 Captain America sales numbers returned to the level of the Civil War issues (#22-24).
Let me start out by saying that we saw a 200% increase with the One Year Later issue - which was Flash: The Fastest Man Alive #1, from the last issue of the series The Flash - issue #230.
However, that number quickly fell. Issue #2 was only 100% over the old series numbers (#228-230's average) and by issue #10 it was down to about 6% over the earlier series and held tight there until....
The final issue of the series, where Bart meets an untimely end, was issue #13. So far that issue has sold 130% over the average per issue sales of Flash: The Fastest Man Alive #9-12.
Now we just have to see where the book ends up when it returns this fall, back to the original numbering.
So there you go - it seems that events, in this case apparent deaths of characters, definitely do sell more comic books.