Originally Posted by
USMCSS
Ok, this is getting out of hand as I should have known it would; this will be my last reply on this subject. FWAAA, you state that if the Grenade went off it wouldn't hurt anyone more then x feet away. What to you is x; an m67 Fragmentation Grenade has a casualty radius of about 15 meters; 90 feet is a large radius, and that’s not to say the metal won't fly further than that.
90 feet may be a large radius, but 15 meters is not 90 feet.
It would be safe to say, given the totality of the circumstances, that getting everyone away from the area would be more than sufficiently prudent. You have a low probability of it actually being a grenade. If it is a grenade you a low probability of an actual grenade detonating. If it actually detonates you have a low probability of casualties for people at least X meters away and behind some barrier (wall, etc.). A low probability times a low probability times a low probability is a very low probability.
I'd say clearing the general area would be more than sufficient.