The causes of this crash seem more mysterious with the passage of a day.

For the record, the human aspects have been clarified. The airplane was owned by a prominent dentist and businessman from Redlands, California. Nine of the people killed were his family members: two daughters, their husbands, and the two families' total of five small children -- the owner's grandchildren. The other five people aboard were the pilot and another young family. (Fourteen people in all, not 17 as in some early reports.)

Again with the caveat that no one knows what happened, the fact that there were so many people aboard magnifies the tragedy but would not seem to have caused a crash. If an airplane is too heavy or has the weight misallocated between the front and rear of the plane, that problem usually shows up on takeoff or early in the flight. (As, for instance, in the crash that killed the singer Aaliyah and eight others in 2001, when the plane was too heavy and its center-of-gravity was too far aft. ) Too much weight can affect the way an airplane handles in turns and increase the risk that while turning it would "stall," or fall out of the sky. But with so little information, any such train of thought is pure speculation.

Deepest sympathies to the families and communities affected by this tragedy.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.