Buried in Concrete

[Rsmyth]

In another post Betty O mentioned that Lewis Powell is buried under 6' of concrete. We know that for security reasons Lincoln and George Pullman were also. In the case of Lincoln, it was his son who was worried about the remains being disturbed. There had already been one attempt. Pullman himself was worried that former workers or union sympathizers would take revenge on his corpse.

Who else took these precautions?