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.
Iran could be producing enriched uranium in a few months, the head of the UN nuclear watchdog Rafael Grossi was quoted as saying on Sunday, raising doubts about how effective US strikes to destroy Tehran's nuclear programme have been.
The Jerusalem District Court has cancelled this week's hearings in Prime Minister Benjamin Netanyahu's long-running corruption trial, accepting a request the Israeli leader made citing classified diplomatic and security grounds.
The Israeli military ordered Palestinians to evacuate areas in northern Gaza on Sunday before intensified fighting against Hamas, as US President Donald Trump called for an end to the war amid renewed efforts to broker a ceasefire.
Russia used hundreds of drones, cruise and ballistic missiles to attack western, southern and central Ukraine overnight, damaging homes and infrastructure and injuring at least six people, local authorities said on Sunday.
At least seven Palestinians were killed and several others injured early Sunday in a series of Israeli airstrikes targeting Gaza City and Khan Younis in the southern Gaza Strip, Palestinian News & Information Agency (WAFA) reported.