If a president is warned about the potential of something, then it is his job to assess the veracity of it, the threat level, and then to create policies/programs/stockpiles to address it should it happen.
Fact is, none of them did. But seems to me that Trump is bearing all the blame for this. Even if he could have, he wouldn't have been able to. Being constantly obstructed by political opposition in Congress made sure he could get very little done in those 3 years.
Moreover, the Democrats in neither house had enough foresight to propose legislation addressing this issue. So why is it just Trump?