What makes you think it was accidental?
Does one attack a vacant lot from three sides or are we to believe Wesley intended to attack three different building bordering the "vacant lot".
It was perfect execution of realpolitik. Chinese anger extinguished the fire Clinton was under for his pro-Chinese activities!
One story, probably fictitious, blamed CIA personnel in an office that tracks nuclear-biological-chemical weapons in the Third World. Allegedly Valerie Plame worked there at the time. They believed the Serbs had chemical weapons in a warehouse in Belgrade. They used an over-the-counter street map to locate the address and determine coordinates from their office in Virginia. Then they submitted a NATO targeting order containing their apparently erroneous numbers.