Sec. 7.01. SURVIVING SPOUSE OF FIREFIGHTER. If a firefighter dies before retirement, the firefighter's surviving spouse is entitled to receive an immediate monthly benefit from the fund of 75 percent of the service retirement benefit that the firefighter would have received if the firefighter had retired on the date of death, but not less than 75 percent of the monthly payment the decedent would have received based on 20 years of service credit.