I found it on this site:
http://www.brestonline.com/History/bh6.shtml
The Brest fortress was the place where the war made its first thundering step which broke the silence of that memorial dawn in June 1941. By the beginning of the war the fortress had lost its defence significance due to the powerful weapons and new military tactics.
Some of the fortifications were destroyed, and the fortress was used by the Soviet army only for billeting the troops. Soviet frontier-guards first were attacked on. The detachment of the lieutenant Kizhevatov armed with guns and grenades repulsed several tank attacks. Having big losses the frontier-guards withdrew to the fortress which became the main center of resistance on the border.
Five hours after the start of the war Germans encircled the fortress and entered the city. The street fights began. Having advantage in arms and manpower nazi quickly suppressed the resistance in the city and continued to move eastward.
The fortress made a prolonged defence against the Germans. The 45th division formed in the Hitler’s native land in Austria was storming the fortress. The division was enforced by three artillery regiments. 500 cannons took the fortress under fire, 600 bombs were thrown on the fortifications.
Old Russian fortifications became impregnable for armed to the teeth Nazi. The participant of the German offence Rudolf Gschopf remembers: “We believed the fortress was turned into the pile of ruins. Right after the artillery fire the infantry crossed the Boog river and tried to take the fortress by quick and energetic offence. We got disillusioned. Russians were caught in beds by our fire.
Nevertheless, they amazingly quickly recovered, formed fighting groups and organised selfless and persistent defence... Our losses in manpower, particularly in officers, became of sorrowful rate. Numerous Russian soldiers hidden and camouflaged in the bushes on the western island did not let our reinforcements pass. On the first day of the war two headquarters of our regiments were encircled and destroyed. The commanders of the regiments were killed.”
The attempt to take the fortress instantly failed, and the its siege began. On the 24th of June, two days after the war started, the united command of the Soviet troops in the fortress was created headed by captain I.N. Zubachev and political officer E.M. Fomin to organise more effective defence.
Cut from the outside world, starving and parched with thirst, they stood firm and died the death of heroes. Nazi had to pay a high price for every fort, every casemate, every stone of the fortress. The fortress was constantly under artillery fire. Neither flame-throwers and tear gas nor tank attacks and air attacks broke the defence.
When nazi took ground fortifications soviet soldiers continued fighting in the underground. The heroic defence lasted almost a month when the Soviet-German front line was far in the East. Even the enemy was shocked at the courage of the fortress defenders. “Officers and men has kept fighting till the last minute. The demand to surrender... had no impact on them” (from a report of the Staff of the Armies’ Group “Center” to its Command). Soldiers fought to the last.
WE ARE DYING
HONOURABLY...
WE SHALL DIE BUT NOT
ABANDON THE FORTRESS.
MOTHERLAND, FAREWELL!
The long-suffering walls of the fortress conveyed these words.
Some historians claim though, that Soviet soldiers did not want to leave the fortress and try to go to the East because they were actually secret police officers who committed a lot of crimes agains local population just before the war.
Thus, they had little chances to survive on their way to the East and had nothing else to do as to stay in the fortress and fight against Germans from whom they could not expect mercy either. Nevertheless, the fact that these soldiers made a prolonged defence lacking water, food and amunition makes them heroes.