Seriously. If you see a bright flash, you are seeing by definition a large energy release. Large energy releases are quite often accompanied by things flying through the air, typically at high speed. You will typically have a moment or two to get down on the ground before any of things intersect your position. In other word, be smart, like Yulia Karbysheva:
At School No. 37 in Chelyabinsk, a quick-thinking substitute teacher, Yulia Karbysheva, got all 44 of her fourth-graders out of harm’s way as the meteor lighted up the sky, the Interfax news agency reported. After the intense bright flash of its explosion, the children rushed to the windows, but before the shock wave could hit, she commanded them to get under their desks.
Karbysheva was showered with glass and debris, but the children were unharmed. With a cut to a tendon in her left hand and a gash on her left thigh, she led her class to safety outdoors. The doctor treating her Saturday at Hospital No. 9 told Interfax she would recover.
Via Instapundit. I know, I know: 1950s public safety films are often unintentionally hysterical. They were also produced by people who typically spent between five and eight years of their lives dealing with other people actively trying to kill them with high explosives/shrapnel. So assume that the producers might actually have known what the heck they were talking about.