As of 2010 there were 81,489,445 people between 45 and 64.
Assuming the low end of an unchecked spread being 60% of the population that is 48,899,073 infected people.
If only .9% of them die (which would be higher with an overwhelmed healthcare system but) that is 440,091 dead. Just in that age range.
I guarantee that is going to include people you know unless you are hit the lotto lucky. Mowing the grass looks easy, until you realize each blade is a person with a family.