There were two explosions at the Chernobyl nuclear power station. The first explosion destroyed the core of Reactor number 4. The second explosion, which was much more powerful, shot burning lumps of graphite and reactor fuel into the air. These lumps landed in various places causing many fires. In all, the explosion had created a crater with burning graphite and about 30 fires in other places around the plant. The fires were the first emergency.

The fire crew in the Chernobyl area responded immediately after receiving an alarm from the plant. First on the scene were 3 fire engines. Seeing that this was not enough, Lieutenant Pravik (commander of the Chernobyl fire crew) sent an emergency signal to Pripyat, Chernobyl town, and the whole Kiev region asking for them to mobilize their fire brigades.

Some of the first firefighters climbed into the machine hall to fight the fire there. When the Pripyat fire brigade arrived just moments later, they decided to fight the fire by going into the reactor building. Major Leonid Telyatnikov, commander of a second fire station in Pripyat reacted to the emergency call and was on scene about 10 minutes after the original fire fighters had started their job. He took overall command and climbed onto the roof of Reactor number 3, which had many fires on it. Even more dangerous was that Reactor number 3 was still operating. It was clear that the most important thing to do was to keep the fire from collapsing the roof of Reactor number 3, which would cause an even greater disaster. Unsuccessful in their efforts, the firefighters were replaced by the Kiev fire brigade.

At 6:35 AM, about four and a half hours after the explosion, all of the fires were extinguished, except the graphite fire inside the reactor crater, by 37 fire crews consisting of 186 firemen and 81 fire engines. Nine days later, using sand, boron, dolomite, clay and lead to smother the fire from airdrops by helicopter, the main graphite fire in the reactor was extinguished, after it had already caused the main release of radioactivity into the environment.

Many of those firefighters who battled the fire from the reactor building died. Fire fighters who had been on the roof of Reactor number 3 suffered later from acute radiation sickness, but most survived.

It was decided that the Chernobyl plant was perhaps not best suited for handling fires such as those that occurred in the explosion. The roofs of the reactor buildings were made of an easily flammable material, bitumen. Also, the firemen were not adequately prepared. Firemen in other nuclear stations in other countries wear protective clothing and breathe through special respirators. The fire fighters at Chernobyl had nothing of this kind. There also had never been a fire-drill at the Chernobyl nuclear station. Many of the firefighters did not even know what they were fighting, they did not even know the dangers of radiation, much less that they were surrounded by it at the time. No account was ever taken of the possibility of radiation.

Later, in August of 1986, Soviet authorities at the IAEA meeting were advised to provide systems for "fire-fighting with specific provisions for nuclear safety", provide firemen with clothing that can protect from high temperatures and radioactive contamination, and to use less flammable building materials.