Well, nobody you know died...
Measles and whooping cough can be deadly diseases though. In England, there were 85 deaths per year from measles in the 60s (up to 1968 when the vaccine was introduced) and 140 per year in the 50s. And
in the United States, measles caused 450 reported deaths and 4,000 cases of encephalitis annually before measles vaccine became available in the mid-1960s.
We had an unfounded whooping cough vaccine scare in England in the late 70s - immunisation coverage dropped to 30% in 1975 resulting in major epidemics in 1977/79 and 1981/83. From 1978 to 1982 there were 44 deaths from pertussis.
How old were the people who died? When I was a child the general opinion was that the five children's diseases weren't so bad if you got them when you were young. I know of nobody who died. I had German measles when I was five, and my main memory of that is my mother teaching me how to knit .
I have figures for measles mortality by age (England and Wales) from 1980 onwards:
http://www.hpa.org.uk/web/HPAweb&HPAwebStandard/HPAweb_C/1195733811885 and the age group with most deaths in the 80s for 8 out of 10 years is 1-4 years old. The 15+ age group tends to be second - but then, that is by far the largest group.
If you want to look at what happened in relatively recent outbreaks...
"Three children (aged 6 months, 4 years, and 10 years, respectively) died. The remaining 125 (21%) cases of identified measles-associated hospitalizations occurred among persons aged >15 years, including three additional cases of encephalitis and one measles-associated death attributed to respiratory failure in a person aged 29 years."
http://www.cdc.gov/mmwR/preview/mmwrhtml/mm5243a4.htm
"The case-fatality rate for children aged 5 to 19 years (0.1%) was five to six times lower than that for preschool-age children and adults."
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1022280/pdf/westjmed00074-0031.pdf The case fatality rate of 1 in 1000 in children aged 5 to 19 is actually higher than I'd expected; that the rate in preschool-age children and adults is reported as being around 1 in 200 is pretty shocking.
In the absence of a vaccine against measles, I don't think measles parties for schoolchildren were necessarily a bad idea given the lower fatality rate. Although, of course, and child who caught the disease at a measles party would have been at risk of passing it on to younger siblings or adults. (A measles party
now, in an era when we have a safe and effective vaccine, would of course be a monstrously stupid idea. Measles parties may have been a pragmatic way of protecting school-age children at the possible expense of others but vaccination is win-win: you protect yourselves and others.)
As far as I know, infants are most at risk when it comes to pertussis. This supports my recollection:
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5128a2.htm "A total of 17 deaths of persons having pertussis symptom onset in 2000 were reported to CDC by 12 states. All deaths occurred among infants born in the United States, with onset of pertussis symptoms at age <4 months."
I note that you refer to German measles, something that I haven't claimed to be a deadly disease. Rubella is quite different to measles and tends to be a mild, self-limiting disease. The big problem with rubella is the risk it poses to pregnant women.