Why do Christians use the tragedy in Oklahoma to recruit followers?

Don't they have any respect for the victims?

In all seriousness, an elderly couple came to my door this morning. They told me they were doing "Christian work" and wanted to know how I felt about all the disasters and terrible events happening in the world today. I rarely have religious people come to my door, perhaps once a year or less, so this was unusual.

I told them I am an atheist and not interested, and they said good bye, thanked me for answering the door, and left. Afterwards I started to think about what they were saying and the timing of their visit.

It strikes me as rather poor taste to recruit followers by taking advantage of a tragedy like the devastation caused by the OK tornado. Even if they had long planned to go door to door in my neighborhood today, you'd think they postpone just for appearance's sake.

Do Christians simply lack any sensitivity to the pain of others and the inappropriateness of using such events for their own purposes?

Are Christians out in force today trying to spin the OK tragedy into a reason to join their churches, or is this an isolated incident?