As someone who has experienced SSD failure first hand, yes it does happen at no they are not infallible. Just ask Linus:
"The timing absolutely sucks, but it looks like the SSD in my main workstation just died on me.
I had pushed out most of my pulls today, so realistically I didn't lose a lot of work. However, any people having outstanding pull requests or patches that they expected me to merge that are not in the current tree on git.kernel.org, you may want to re-send the email, because I had archived emails as I merged them, and I may not have found all the ones that never made it out.. I know a few involved, but....
That said, wait until tomorrow. I'll try to see if I can recover the disk, but right now my machine refuses to even see the boot sector on it, and tries to boot from the network instead. So I'm not all that hopeful.
If worst comes to worst, I'll just do the last next days of the merge window on the laptop that I was planning on finishing it off with anyway, since I have travel coming up. At least this didn't happen at the very beginning of the merge window...
Source: RIP - dead harddisk..
I have a new mSATA SSD on order right now to replace the one that failed in my Laptop, so I know how he feels. Daily backups with Back In Time help to reassure me somewhat.