What is the ruling regarding the liability of the deceased parties when the causal chain extends further (e.g., first pulls second, second pulls third, third pulls fourth, and all perish)?

Primary text

If the third person pulls a fourth, and all perish by falling on one another, the fourth party has no liability as he performed no action affecting himself or others. Regarding the fourth person's diya, one view states it is on the *aqilah* of the third party as the direct puller. The second view holds it is upon the *aqilah* of the first, second, and third parties equally, as the fourth died due to the pulls of all three. Concerning the first person's diya, since he died due to his pull, the second's pull, and the third's pull, one view states his own action is nullified, and his diya is due equally from the *aqilah* of the second and third. A second view holds two-thirds of his diya is due from the *aqilah* of the second and third, voiding the portion corresponding to his own action. A third view states one-third of his diya is due to his heirs from his *aqilah*. The second person's diya is subject to the same three opinions as the first, as he died from the three actions. The third person's liability is subject to these three opinions, plus two others: one stating his entire diya is on the second person as the direct puller, nullifying the actions of others; the second stating half his diya is due from his *aqilah*, voiding the other half corresponding to his own action.