actually it sounds like the thing was more a matter of extreme stupidity rather an run-of-the-mill accident:
An employee in the office said [Ayyas al-]Alayli, 36, took the grenade from a shelf where it had been sitting and threw it on the floor to show Mugharbel, a secretary, that it would not explode.as i said, i had no idea this had happened when i was there. the city was swarming with soldiers searching cars for bombs before this explosion happened, and they were doing the same after. hurricane katrina came up more in conversations than an explosion in the same city where we were talking.
i can't imagine any other city having such a non-reaction. but those guys are always on high alert. the military is already everywhere searching for bombs and generally maintaining a highly visible presence. i don't know if they can crank up the edginess any higher. but last night, when i was being driven around the city by a local beiruti and remarked about how strange it is to see soldiers everywhere with heavy weapons she replied "i don't even see them anymore."