Best Way To Follow Objects?

I have an ai and I am looking for him to move to an object (a tower). Which is simple however I have three towers and I want him to move to the first and when it dies move to the second on so on. I’m stuck on which approach I should take trying to tackle this.

Make an array of your target objects (in your case, towers)
Use an integer variable as an index to access the target objects array. When a target (tower) dies, increase this integer by one.

Step by step:

Integer = 0.
Access element 0 of array.
(With the array output node plugged in) call “Simple Move to Actor”
—time passes—
Tower dies.
Tower increases integer by 1.

Integer = 1.
Access element 1 of array
… etc