Femi Adesina the presidential aide in an interview reveled why Buhari did not say anything about the tragic incident at Lekki.

The Presidency stated that it was too early for the president to give any comments on the issue because further investigations were being done.
“The Defense Headquarters issued a statement to say that it was investigating the matter. Lagos State Governor has also set up a probe panel to investigate what really happened.
“So, the President couldn’t have said anything because it would be premature and presumptuous while investigation is ongoing. It is after investigation has been concluded that he can speak on the matter.”
Source: Gossips24.Com