Blocks are all acting correctly, bomb is acting correctly

Assets/Scripts/Damagers/DamagerBase.cs

@@ -1,5 +1,16 @@
-using UnityEngine;
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
 
 public class DamagerBase : MonoBehaviour {
 	public int value = 1;
+
+	void Awake() {
+		StartCoroutine (DestroySelfAfter (30));
+	}
+
+	IEnumerator DestroySelfAfter(float delay) {
+		yield return new WaitForSeconds (delay);
+		Destroy (gameObject);
+	}
 }

Assets/Scripts/Damagers/IceDamager.cs

@@ -1,12 +0,0 @@
-using System.Collections;
-using System.Collections.Generic;
-using UnityEngine;
-
-//shootable
-public class IceDamager : DamagerBase {
-	void OnTriggerEnter2D(Collider2D collider) {
-		if (collider.gameObject.GetComponent<IceDamager> () == null) { //pass through other instances of self
-			Destroy (gameObject);
-		}
-	}
-}

Assets/Scripts/Damagers/IceDamager.cs.meta

@@ -1,13 +0,0 @@
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-guid: 4b0265e5d9f1a804aaa77a77754f51e0
-timeCreated: 1524281573
-licenseType: Free
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
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-  assetBundleName: 
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