If the suction was that strong there, a grate would only guarantee the next person to dive too close would get sucked against the grate--and possibly be there long enough to run out of air.
If the guy got pulled through and survived that unhurt, the design is good.
ITs hard to guarantee against the stupidity of people
They need a grate, but it must be far enough away that the current is NOT strong enough to suck you against it.
This IS a huge security breach- and there should be a grate