PowerPoint Show by Andrew

A fire engulfed a landmark building in Tehran, Iran, Thursday morning, leading to a complete collapse that may have killed as many as 30 people, including many firefighters.

The 17-story Plasco Building, once the tallest in Iran, fell while firefighters were actively battling the blaze. Iran's state-run Press TV said dozens of firefighters were killed, more than 20 remain missing, and an unknown number of civilians may be trapped under the rubble, though most are thought to have escaped. Emergency responders immediately began digging through the rubble, looking for survivors.

Fire erupts from the Plasco building in Tehran on January 19, 2017.

Firefighters battle a blaze that engulfed Iran's oldest high-rise, the 17-story Plasco building, in downtown Tehran on January 19, 2017.

Iranian firefighters run towards the Plasco building engulfed by a fire in central Tehran on January 19, 2017.

Firefighters battle a blaze at the 17-story Plasco building in Tehran.

Firefighters try to put out the Plasco building fire in Tehran.

Firefighters carry a wounded comrade as they battle the blaze.

Iranians watch the Plasco building where smoke rises from its windows.

Firefighters work to extinguish fire at the Plasco building.

The blazing Plasco building begins to collapse.

Firefighters and spectators stand and watch as dust and smoke fill the air after the collapse of the Plasco building.

After the collapse.

Firefighters return to work after the building collapsed.

Rescue workers begin the search for victims.

A firefighter collapses from emotion.

A firefighter consoles his comrade after the collapse of Iran's oldest high-rise on January 19, 2017.

Firefighters react at the news of missing comrades.

Firefighters work at the scene of the collapsed Plasco building.

Firefighters work at the scene.

Searching for bodies after the collapse.

firefighter stands atop the ruins of the collapsed Plasco building after it was engulfed by a fire, in central Tehran, Iran, on January 19, 2017.