Stay away from windows, shards of glass flying at high speeds are a big factor in indoor deaths from blasts. Many embassies have breathable curtains with weights on the bottom, to catch any glass while letting air pass through
Some people in Hiroshima had to have surgery later in life to remove other people's teeth from their bodies.
This is one of the scariest and ugliest thing I've ever read about Hiroshima.
https://www.youtube.com/watch?v=6eCd3qYCC6E
With the bomb curtain I mentioned, https://www.youtube.com/watch?v=WKiig392a3I
There are bomb films similar to what you described, but they need to be added with a blast resistant window frame
https://www.youtube.com/watch?v=kKjVbytYFHA
I presented these videos during a class discussing the effects of nuclear weapons and explosions