How do I get the number of players touching a part? (Touched event)

You could try this but I don't know if it works because I didn't try it

local part = script.Parent -- The Part

local Touching = {  } -- Everyone who touches the part

part.Touched:Connect(function(hit) -- Fires when someone touches it
    local char = hit.Parent -- Gets the character
    if game.Players:GetPlayerFromCharacter(char) then -- Checks to see if it is actually a player
        table.insert(Touching, game.Players:GetPlayerFromCharacter(char)) -- Adds them to the touching table
    end
    if #Touching >= 3 then -- if there is 3 or more people touching
        for i,v in pairs(Touching) do
            v.Character.Humanoid.Health = 0 -- kills
            table.remove(Touching, i) -- removes player from the table
        end

    end
end)

part.TouchEnded:Connect(function(hit)
    local char = hit.Parent -- Gets the character
    if game.Players:GetPlayerFromCharacter(char) then -- Checks to see if it is actually a player
        for i,v in pairs(Touching) do
            if v.Name == game.Players:GetPlayerFromCharacter(char).Name then -- finds where player is located in the table
                table.remove(Touching, i) -- removes player from table
            end
        end
    end
end)

You can try making a number value and then in your script put:

local part = script.Parent

part.Touched:Connect(function(hit)
    local PlrsTouchingCount = script.Parent.NumberValue --I said NumberValue but make sure to change this into the name of your number value
    PlrsTouchingCount.Value = PlrsTouchingCount.Value+1
end)

--Now we are gonna make it so when they are not touching the part then it doesnt count them in the NumberValue

part.TouchEnded:Connect(function(hit)
    local PlrsTouchingCount = script.Parent.NumberValue --Remember change the word NumberValue into the name of your real NumberValue
    PlrsTouchingCount.Value = PlrsTouchingCount.Value-1
end)

Hope this helps :D