Parts of the northern section of the silos had already collapsed in recent weeks after a fire burned through the structures for several weeks, scattering tonnes of grains amid hot weather.
People living around the port said they were staying indoors to keep away from the heavy smoke caused by the collapse.
For many, the damage recalled the fire that triggered the explosion of tonnes of improperly stored ammonium nitrate in 2020.
More than 190 people were killed and 6,000 others were injured in the explosion on Aug. 4, 2020, that destroyed large parts of Beirut and displaced some 300,000 people.
Experts have said that the silos in the area absorbed much of the impact of the blast two years ago, sparing the city even worse damage.
The families of the victims and activists have called on the government to preserve the silos to remind people of Lebanon’s worst peacetime tragedy.
Their pleas followed a decision by the Lebanese authorities in April to tear down the silos.
“We are sad, but the southern part is still standing to keep reminding all the Lebanese of the catalyst explosion that killed my brother and others.
William Noun, brother to a firefighter who lost his life in the port blast told dpa.
“Even if one of the columns remains standing this will always remind us to keep working for justice,’’ Noun, who is also the spokesman of the port victims’ families, added.