Contrary to the internet meme, the missiles were right on target. The base received adequate warning both from our own systems and the Iranians. The missiles hit their objectives and in some instances right in the middle. That no one died is a function of the warning as well a preparedness.
The rest is fake news or bad reporting.
This report on the effects of bombing in Vietnam suggests that even a very basic entrenchment topped up with sandbags can protect the people sheltering within from anything but a close hit:
https://eml.berkeley.edu/~groland/pubs/vietnam-bombs_19oct05.pdf
[Conventional iron bombs, free-falling and unguided. “These account for the greatest fraction of the total weight of aerial munitions used; they are carried by fighter-bombers, attack bombers, and high-flying strategic bombers (B-52s), and delivered by free fall. ... Weight ranges from 100 pounds to 3000 pounds; most common range is 500-1000 pounds; about 50 percent of weight is explosive. The bomb works mostly by blast effect, although shrapnel from the casing is also important. ... The crater from a 500-lb. bomb with impact fuze (e.g., MK 82) is typically 30 feet in diameter and 15 feet deep (this obviously varies greatly with the terrain). Shrapnel is important over a zone about 200 feet in diameter. Simple shelters (sandbags, earthworks, even bamboo) protect against all but close hits.” (Littauer et al 1972: 222). “The biggest of [the GP bombs] was the 15,000-pound BLU-82B ‘Daisy Cutter’.” (Doleman 1984: 127)]