The northern section of the grain silos damaged two years ago by a blast at the Beirut port collapsed early on Tuesday after warnings the structure was leaning too far to stay up.
The crash sent a cloud of brown-grey dust billowing over the waterfront, the LBCI television station reported. There were no immediate reports of injuries.
The huge explosion at the port on August 4, 2020, killed more than 220 people and gutted the northern section of the grain silos, leaving wheat and corn spilling out in the sun.
Recently, a fire had been smouldering in the silos for weeks, which officials said was the result of summer heat igniting fermenting grain left rotting.
Part of the structure collapsed on July 31 and another section fell on August 4, the second anniversary of the blast.
On Sunday, the health ministry said dust samples from around the port showed that the air contained high amounts of common mould, which would not be dangerous unless inhaled in large quantities over a long period of time.
Indonesian rescuers were searching on Sunday for 140 people from a passenger ship that sank in the Java Sea after 103 others were evacuated, one of whom died, a search and rescue agency official said.
Authorities in the Philippines said on Sunday it could take weeks or months to identify the victims of a ferry fire that killed 76 people, as forensic experts begin collecting and comparing DNA samples and investigators determine the cause.
Saudi Arabia shut its East-West oil pipeline on Friday after it was hit in a drone attack, disrupting a key route used to bypass shipping problems in the Strait of Hormuz.
BRICS members agreed on a joint declaration on Saturday, expected to condemn unilateral aggression by any country without naming individual states, according to sources cited by Reuters.
Philippine rescuers recovered 41 more charred remains from a ferry fire, authorities said on Saturday, raising the death toll to 76 and leaving 13 people unaccounted for, as forensic teams faced the daunting task of identifying the victims.