The contractor estimate for the cost to repair the damage is approximately 93k.

Perhaps my son being one of the tenants will help to mitigate the damage?

This can help mitigate potential damages down the road. 

In addition, habitual late payments over the grace period can result in eviction which is very damaging and expensive.Bi-weekly rent is $225/biweekly period = $5859/year

Like Detroit, Saint Louis is incredibly "block by block" where one area is experiencing gentrification or at least just a stable middle class feel and that might only be 100 yards away from a street that will be un rentable, un managemeable, and honestly a bad place to get out of your car.  

Insurance will cover damage to their possessions, but you are talking about inability to use the apartment, not their possessions.Lack of water/sewer service means the apartment is uninhabitable.

Unless these folks are the money managers for a money laundering scheme designed to clean blocks of cash with large denominations and private party placement and don't care about 5% US Bond scrutiny (sovereign wealth comes to mind), my first thought when I saw the 3% interest rate was skepticism.  

@Carl W., first off you never state who should be paying for the damage? 

Mind you; there are no physical damage to the garage door itself.

PM's who block you from contacting a tenant usually have something to hide.