Oh man! That's way not good!
As far as I know, you don't have much choice but to cut off the broken branches. Perhaps there's a small branch forming at the base? It's not uncommon for there to be one and this would mean ther's a very good chance it'll be fine. Even if there's not, I think there is a decent chance it may survive.
Starting cuttings is a very good idea - no sense all those good branches going to waste.
Keep us posted on what you do and how it turns out.
Good luck.
Barb

Thanks Barb. I think I'll have luck with the cuttings but don't know about the main plant. There is no sign of growth at the bottom where I need to cut. It could have been worse...... I have a bunch of pots in that corner and that hibiscus is the only one that got smashed.

When I original looked at your photos, it was my opinion that 2 of the hibiscus looked like they had been given a bloom stimulant such as Cycocel. It's really tough to tell by just one photo, but they had that look to them. Anyway, if it is one of those 2, you will probably not have a lot of luck rooting the cuttings. Cycocel(or something similar) severely stunts the growth until it completely grows out of the system - makes it VERY tough to root the cuttings.

If it was the tall lanky hibiscus that was broken, you will stand a much better chance at rooting them.

The only other question is are these grafted hibiscus? It's easier to find grafted hybrids than it is to find "own root". If it's grafted and you only have a 1/2 inch of trunk, you probably have the root stock left. It's a 50/50 chance that it will be able to put out new growth, but if it's rootstock, it's going to be an entirely different plant.

Thanks for the feedback minibim. It was the short one that was smashed. I am not sure how to tell if it was given bloom stimulant. I bought them from A Touch of the Tropics at the garden show. I guess all I can do is try. I am so sad.

I still don't know how to prune the tall lanky one. Any suggestions??

Live and learn. :)