Two 231-ft.-long Boeing 747 jumbo jets collided on the ground. Taking off down a runway visible for less than a sixth of its length, KLM 4805 smashed into Pan American 1736.

The sweet scent of flowers reaching their boats inspired ancient Romans and Greeks to call them “the Fortunate Islands.” The refreshingly mild and breezy climate was praised by more modern travelers as “perpetual spring.” But early natives of the Canary Islands,*70 miles off the northwest coast of Africa, knew…