So as I was preloading CiV last night and when it was about 92% done, my PC unexpectedly froze when I was trying to open up the CiV PDF manual. After 5 minutes of not having any responses on my frozen computer screen, I had no choice but to press the power button to reboot the computer. 
After my computer restarted, I immediately logged into Steam and was a bit relieved to find it resuming downloading, which it did finish eventually without any issues.....
However, I am still really worried that shutting down my PC in the middle of a Steam download may lead to corrupted game files.
And I am one of those unfortunate people who had to wait till Friday to play CiV. So there's no way to tell whether everything will be alright.
Can anyone who ever used Steam let me know whether downloaded files will be corrupted/broken if I shut down my PC like that?
Thanks in advance!!!

After my computer restarted, I immediately logged into Steam and was a bit relieved to find it resuming downloading, which it did finish eventually without any issues.....
However, I am still really worried that shutting down my PC in the middle of a Steam download may lead to corrupted game files.

Can anyone who ever used Steam let me know whether downloaded files will be corrupted/broken if I shut down my PC like that?
Thanks in advance!!!