when the landslide hit

[Maybo]

Why is a comma not needed after "hit"?

They said that when the landslide hit they heard "a roaring, like heavy machinery" and fled to the top of their three-storey home just before the lower floors were inundated. (Japan landslide: Elderly couple among survivors pulled from buried homes by BBC)

 

[GoesStation]

I'd use a comma.

 

[Charlie Bernstein]

I would, too.

Over the years, I've noticed that when the meaning is clear without a comma, British writers are more likely to omit it than an American is.

 

[probus]

To some exent, Maybo, commas are a matter of personal taste. Two respected colleagues have said they would use a comma. I, on the other hand, prefer it without.

 

[Rover_KE]

I'm a comma minimalist, so for me it's fine as is.

 

[emsr2d2]

An argument can be made for two commas.

They said that, when the landslide hit, they heard ...

I'm not saying they should be used but "They said that they heard ..." is complete and grammatical, and "when the landslide hit" is additional (but very relevant) information.

 

[jutfrank]

Don't ask why something is not needed. Ask why something is needed.

Commas are used for a reason, which is to break up sentences into more easily digestible parts. The writer of this sentence considered that his/her readers would manage to read the sentence fine without a comma.

 

[Charlie Bernstein]

I rest my case. (See 2, 3, 4, and 5.)