Hubo vs Había

Question

In the question, How would you say "There was an accident on the motorway" the nearest correct answer I can find is "Había un accidente...", and there isn't the option for preterite 'hubo'. However, because accidents are one time actions with clear beginnings and ends, it's more appropriate to use the preterite tense in this case. In fact, this particular sentence is a very common one to use when explaining the differences between the two conjugations and especially to illustrate why imperfect simply doesn't work here.

Accepted Answer

Thanks Alan.

I'm always reluctant to allow for the possibility of other actions going on that aren't mentioned as that can open up boundless horizons that allow for any number of interpretations. If the 'había' clause had been followed by a 'main action' clause in preterite - and perhaps connected by conjunction like 'mientras' or 'cuando' - I might feel more comfortable accepting the reasoning of this blog post in relation to my post. But, as an accident is such a short term action, I'm not even sure those usual rules of preterite with imperfect would apply in this case.

Answer

Actually both are possible depending on the context. You might find this link useful, since it uses Hubo/Habia un accidente as its main example.

http://preguntolandia.blogspot.com/2010/05/hubo-vs-habia.html

Answer

Hola Graeme
As Alan very rightly said, it depends on the context, but we must also think of it as "how the speaker is seeing that action in his/her head" at the moment of speaking. If I say: 
Hubo un accidente de tráfico en la M40. 
what I am seeing in my head is the end of that event. I may see the police clearing the congested traffic once it is all clear, for example. 
If I had said instead:
Había un accidente de tráfico en la M40.
What I see in my head is the actual cars involved in the accident on the side of the road. Using había is describing what was happening, not seeing it as an "ended" event. 
This difference in use is common for all verbs. We have a lesson about this general difference. 
I hope this helps,
Saludos,
Inma