A woman and her child fell from near the top tier of a multi-story baseball park in San Diego -- a plunge that killed both of them ... and now cops are reportedly calling it suspect.
The horrific incident happened Saturday afternoon not too long before the Padres were set to play at their home field, Petco Park -- when a mother and her 2-year-old son went over an edge on the third level concourse somewhere ... with witnesses claiming the kid went first.
According to the Union-Tribute -- which spoke to eyewitnesses claiming to have first and second-hand accounts -- the mother and son were in a picnic area looking out onto the street side of the stadium, and somehow the boy toppled over a ledge .