how do you take away something using the died event? (SOLVED)

Hey, I'm making a game and I want to know: how can you take away something using the died event? Like a walkspeed boost then take it away if they died? Thanks!

P.S Hers what I think this would be like

Local SpeedBonus = SB
Humanoid.walkSpeed.SB = 1.25
game:GetService('Players').PlayerAdded:connect(function(player)
    player.CharacterAdded:connect(function(character)
        character:WaitForChild("Humanoid").Died:connect(function()
                   Humanoid.walkspeed = 1.25
        end)
    end)
end)

I don't think it's right, but I gave it my all.