N.Y. Vol. Fire. Ben. Law § 11-C
Notwithstanding any provision of this chapter or of any general, special or local law to the contrary, and for the purposes of this chapter, any condition of impairment of health caused by diseases of the lung, resulting in total or partial disability or death to a volunteer firefighter, where such volunteer firefighter successfully passed a physical examination on entry into such service or subsequent thereto, which examination failed to reveal any evidence of such conditions, shall be presumptive evidence that such disability or death (a) was caused by the natural and proximate result of an accident, not caused by such firefighter's own negligence and (b) was incurred in the performance and discharge of duty, unless the contrary be proven by competent evidence.
N.Y. Vol. Fire. Ben. Law § 11-C