Accidents happen. Sometimes really, really bad ones. But that's why we have the word in our language. They happen for lots of reasons, usually stupid ones, but they do happen. This terrible accident seems to have happened because the driver was confused and not able to think clearly enough to stop or redirect his car. That he was 89 years old has to have been a contributing factor. Punishing that man by sending him to prison is not only stupid, but pointless, and probably demanded only by people who need to revenge everything, no matter what the circumstances. We've been seeing a lot of that in the news lately. Instead of automatic incarceration, it might be wise to consider additional testing for elderly drivers.
Yeah, killing 10 people and maiming dozens of others is no big deal. You betcha. Just an accident.