were acquired during his last employment with Osco, which started on September 14, 1991 and ended on November 9, 1991. Neither can we conclude, without competent medical proof, that his death was a product of his illnesses that were diagnosed during his previous employment which ended in March 1991. Indeed, the death of a seaman several months after his repatriation for illness does not necessarily mean that: (a) the seaman died of the same illness; (b) his working conditions increased the risk of contracting the illness which caused his death; and (c) the death is compensable, unless there is some reasonable basis to support otherwise. [20] In the present case, we find no reasonable basis to award the death compensation benefits prayed for by the beneficiaries of Ciriaco. Moreover, we are not persuaded by petitioners argument that if we were to follow the ruling of the CA that the beneficiaries of Ciriaco are not entitled to death benefits under the Standard Employment Contract because Ciriacos death occurred after the term of his contract ended, then it would mean that the deaths of seafarers which are subject to compensation are only those which occur while the seafarers are still on board the vessel in which they are assigned. Petitioners reasoning is flawed. It is clear from the provisions of the Standard Employment Contract that the only condition for compensability of a seafarers death is that such death must occur during the effectivity of the seafarers contract of employment.[21] Nothing in the said Standard Employment Contract requires that the seafarer must have died while on board the sea vessel. Hence, it is possible that death may happen even if the seafarer is not on board the vessel, as in cases where the seafarer has to be taken off the vessel and confined in a land-based medical treatment facility, and yet the death is compensable. Petitioner contends that if the beneficiaries of Ciriaco are not entitled to death benefits, then in the alternative, they should be awarded permanent total disability compensation. We are not convinced. The OSG correctly observed that petitioner did not seek payment of disability benefits in her affidavit-complaint filed with the labor arbiter. A reading of the said affidavit-complaint shows that she only sought payment of death compensation benefits including financial assistance for their minor child as well as burial assistance. In addition, petitioner also prayed for the reimbursement of the expenses they have incurred for the continued medication and hospitalization of Ciriaco. However, nothing in her complaint shows that she raised before the labor arbiter or the NLRC the issue of her or her husbands entitlement to permanent and total disability benefits and it was only in her amended petition filed with the CA that petitioner raised this issue. The resolution of this issue requires the admission and calibration of evidence and since petitioner did not specifically raise this matter in the proceedings before the labor arbiter and even the NLRC, these tribunals were not given a chance to pass upon it in their assailed decisions. Hence, the issue of whether or not Ciriaco or his beneficiaries are entitled to disability benefits can no longer be passed upon on appeal because it was not raised in the tribunals a quo. Well-settled is the rule that issues not raised below