SUPPLEMENT DATED SEPTEMBER 1, 2000, TO
                 THE PROSPECTUS DATED MAY 1, 2000, FOR
                   FIRSTLINE VARIABLE UNIVERSAL LIFE
           FLEXIBLE PREMIUM VARIABLE LIFE INSURANCE POLICIES
                               ISSUED BY
               SECURITY LIFE OF DENVER INSURANCE COMPANY
                                AND ITS
                   SECURITY LIFE SEPARATE ACCOUNT L1

THIS SUPPLEMENT UPDATES CERTAIN INFORMATION CONTAINED IN YOUR PROSPECTUS DATED
MAY 1, 2000. PLEASE READ IT CAREFULLY AND KEEP IT WITH YOUR PROSPECTUS FOR
FUTURE REFERENCE.

The following paragraph is added after the first paragraph on page 31 as part of
"Continuation of Coverage":

         "In some states, if you accept the continuation of coverage
         feature, the death benefit during the continuation of
         coverage period is the account value. There is no
         administrative fee for this feature in these states. Contact
         your agent/registered representative or our customer service
         center to find out which type of continuation of coverage
         applies in your state."


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