ceived by the deceased Retired Tier 6 Plan Member immediately preceding the date of his or her death. The benefit described in this subsection (a)(3) may be modified as provided in subsection (b) of this section. (4) Tier 6 Retired Plan Member's Death While on a Service-Connected Disability Pension. The Qualified Survivor of a Retired Tier 6 Plan Member, who shall die while he or she is receiving a service-connected disability pension pursuant to Section 1706, shall be paid for life a monthly pension in an amount which shall be equal to 80% of the pension received by the deceased Retired Tier 6 Plan Member immediately preceding the date of his or her death, unless the death of the Retired Plan Member occurs within three years after the effective date of his or her pension and is due to service-connected causes, in which case, the Qualified Survivor shall receive, or in a case where an option has been elected pursuant to subsection (b) of this section, may elect to receive, 80% of the Retired Plan Member's Final Average Salary, as modified by the cost of living adjustments made pursuant to Section 1716 of this article since the date of retirement of the Retired Plan Member. The benefit described in this subsection (a)(4) may be modified as provided in subsection (b) of this section. (5) Tier 6 Retired Plan Member's Death While on a Nonservice-Connected Disability Pension. The Qualified Survivor of a Retired Tier 6 Plan Member, who shall die while he or she is receiving a nonservice-connected disability pension pursuant to Section 1706, shall be paid for life a monthly pension in an amount which shall be equal to 70% of the pension received by the deceased Retired Plan Member immediately preceding the date of his or her death. The benefit described in this subsection (a)(5) may be modified as provided in subsection (b) of this section. (6) Tier 6 Plan Member's Nonservice-Connected Death While on Military Leave. The Qualified Survivor of a Tier 6 Plan Member who, while on military leave, is killed as a result of the discharge of his or her military duties shall be paid for life, as a nonservice-connected survivor benefit, a monthly pension in an amount which shall be equal to 50% of the deceased Plan Member's Final Average Salary.