Joseph H. Alexander, Closing In: Marines in the Seizure of Iwo Jima
“ Despite these difficulties, the 27th Marines made good initial gains, reaching the southern and western edges of the first airfield before noon. The 23d Marines landed over Yellow Beach and sustained the brunt of the first round of Japanese combined arms fire. These troops crossed the second terrace only to be confronted by two huge concrete pillboxes, still lethal despite all the pounding. Overcoming these positions proved costly in casualties and time. More fortified positions appeared in the broken ground beyond. ”
