He led an attack against a high precipitous ridge defended by a company of enemy riflemen, who were entrenched in spider holes and supported by well-sealed pillboxes housing automatic weapons with interlocking bands of fire. The terrain was such that only 1 squad could advance at one time; and from a knoll atop a ridge a pillbox covered the only approach with automatic fire. Against this enemy stronghold, S/Sgt. Sjogren led the first squad to open the assault. Deploying his men, he moved forward and was hurling grenades when he saw that his next in command, at the opposite flank, was gravely wounded. Without hesitation he crossed 20 yards of exposed terrain in the face of enemy fire and exploding dynamite charges, moved the man to cover and administered first aid. He then worked his way forward and, advancing directly into the enemy fire, killed 8 Japanese in spider holes guarding the approach to the pillbox. Crawling to within a few feet of the pillbox while his men concentrated their bullets on the fire port, he began dropping grenades through the narrow firing slit. The enemy immediately threw 2 or 3 of these unexploded grenades out, and fragments from one wounded him in the hand and back. However, by hurling grenades through the embrasure faster then the enemy could return them, he succeeded in destroying the occupants. Despite his wounds, he directed his squad to follow him in a systematic attack on the remaining positions, which he eliminated in like manner, taking tremendous risks, overcoming bitter resistance, and never hesitating in his relentless advance. To silence one of the pillboxes, he wrenched a light machinegun out through the embrasure as it was firing before blowing up the occupants with handgrenades. During this action, S/Sgt. Sjogren, by his heroic bravery, aggressiveness, and skill as a soldier, single-handedly killed 43 enemy soldiers and destroyed 9 pillboxes, thereby paving the way for his company's successful advance.