How would changing the verb tenses affect this NYT report?

Question

As a way to improve my grammar, I've been reading New York Times articles, focusing particularly on verb tenses. Here is one section of an article I found of interest:

Mr. Wilansky, who spoke by telephone and checked details with his daughter as he did, said the explosion had taken place around 4 a.m. Monday, when most of the protesters were gathered around a bonfire near the foot of the bridge.

Is my analysis correct?

Had taken place is used because the explosion had occurred before he spoke by telephone. Because the protesters gathered first and then the explosion occurred, the infinitive, to be, takes the simple past not the past perfect.

• had been taking place would mean that a series of explosions had been occurring at least around 4 a.m. but possibly up until the phone call

• was taking place would mean that the explosion was happening as he spoke on the phone around 4 a.m. OR, had this report been issued before 4 a.m. Monday, that the explosion was going to be happening around 4 a.m., but it won't anymore.

• took place would mean he spoke by phone at the same time the explosion happened around 4 a.m.

• Using the present perfect wouldn't make any sense

Sorry for the length...

Answer 1

1. You need to note that the noun explosion is a countable noun, which means you can use the plural form explosions when you want to describe more than one explosion. Therefore, your first assumption is irrelevant. We can know there was only one explosion by reading the explosion which is different from a series of explosions, multiple explosions, a few explosions, etc.

2. Was taking place would mean that the explosion was continuously taking place, which doesn't make much sense unless there were multiple explosions at the time of speaking. An explosion usually doesn't take more than a few seconds to take place. So, generally speaking, you don't need to use the progressive (continuous) aspect for this kind of action.

3. Took place would mean same as had taken place as you can't speak about the explosion if it didn't take place before you speak. It doesn't mean the two actions (speaking and exploding) happened at the same time.

4. You already answered your question with the sentence "Had taken place is used because the explosion had occurred before he spoke by telephone." Using the past perfect, the writer wanted his readers to understand the sequence more clearly.