The data set is available on Kaggle.
The code used to analyse the data is available here.
Plotting the number of casualties by state gives:
This is a little misleading, because CA, TX and so on are large populous states so it is not surprising that the greatest number of casualties came from these states. I added in state populations from 1967 and normalised the casualty rates per state, then plotted the data again:
This map suggests Missouri had a disproportionately large casualty rate normalised by state population compared to other states while California had a relatively low casualty rate.