unity - Method causes OutOfMemory error

If a GameObject in my game has a special ability it triggers it, but I want all the special GameObjects that this GameObject affects to also trigger their abilities, for example if a bomb hits some objects, if these objects are also bombs, trigger them too. I though this would be easy by calling the method that handles all the special abilities recursively, but, as always, it wasn't. Basically what happened is a chain reaction of bullcrap that caused Unity to show an OurOfMemory error. Also makes my PC freeze completely while politely turning all the screens off.

The question is, how can I make it so it triggers all the affected cubes' special abilities, without everything going nuts?

Code:

     //Triggers the cube's special ability, if it has any
    private void TriggerSpecialCubeAbility(GameObject specialCube) {
        switch (specialCube.tag) {

            //Destroy all cubes in a radius from the special cube
            case "Bomb":

                TriggerBombAbility(specialCube);
                break;

            //Destroy all cubes of the same color as the special cube
            case "Lighting":
                TriggerLightingAbility(specialCube);
                break;
            default:
                break;
        }

    }

    private void TriggerBombAbility(GameObject specialCube) {
        var nearbyColliders = Physics2D.OverlapCircleAll(specialCube.transform.position, explosionRadius);
        Instantiate(particles[0], specialCube.transform.position, specialCube.transform.rotation);
        Instantiate(particles[1], specialCube.transform.position, specialCube.transform.rotation);

        foreach (var collider in nearbyColliders) {
            if (collider.tag == "Indestructible")
                return;


            var affectedCube = collider.gameObject;
            TriggerSpecialCubeAbility(affectedCube);
            Destroy(affectedCube);
        }

        destroySelectedCubes = true;
        //          Physics2D.gravity *= -1;
        //          Physics.gravity *= -1;
    }

Answer

First of all, you seem to have a bug in TriggerBombAbility(): that return should be a continue.

Now a quick way to fix your issue of infinite recursion is to devise a way to mark a GameObject as no longer triggerable. For instance you could have a hasBeenTriggered boolean, defaulting to false, and you set it to true before triggering abilities:

       case "Bomb":
            specialCube.hasBeenTriggered = true;
            TriggerBombAbility(specialCube);
            break;

Then you only call TriggerSpecialCubeAbility() if the ability hasn’t already been triggered:

        var affectedCube = collider.gameObject;

        if (!affectedCube.hasBeenTriggered)
        {
            TriggerSpecialCubeAbility(affectedCube);
            Destroy(affectedCube);
        }

Alternatively, you could put that check in TriggerSpecialCubeAbility() itself and do an early exit: Nevermind; this would require a check around Destroy(), too, and is therefore more complicated.