The investigation is focusing on how 2,750 tons of ammonium nitrate, a highly explosive chemical used in fertilizers, came to be stored at the facility for six years, and why nothing was done about it.
International aid flights began to arrive as Lebanon's leaders struggled to deal with the shocking aftermath of Tuesday's blast, crippled by an economic crisis and facing a public that blames chronic mismanagement and corruption among the ruling elite for the disaster.
The explosion at the port killed at least 135 people and wounded about 5,000, Health Minister Hamad Hassan said. Hospitals were overwhelmed — one that was damaged in the blast had to evacuate all its patients to a nearby field for treatment. Buildings were damaged for miles around the city, and Beirut's governor said Wednesday that hundreds of thousands might not be able to return to their homes for two or three months.
It was the worst, most destructive single explosion to strike Lebanon in a history filled with destruction, in a 1975-1990 civil war, conflicts with Israel and periodic terror attacks.
A senior U.S. Defense Department official and member of the U.S. intelligence community said there were no indications the massive explosion that erupted on Tuesday evening in Lebanon's capital was the result of an attack by either a nation state or proxy forces.
Both individuals spoke to The Associated Press under condition of anonymity because they were not authorized to discuss intelligence briefings publicly. Both officials told the AP that at the moment, the explosion seems to have been caused by improper storage of explosives.
Fueling speculation that negligence was to blame for the accident, an official letter circulating online showed the head of the customs department had warned repeatedly over the years that the huge stockpile of ammonium nitrate stored in a hangar in the port was a danger, and asked judicial officials for a ruling on a way to remove it.
Ammonium nitrate is a component of fertilizer that is potentially explosive. The 2,750-ton cargo had been stored at the port since it was confiscated from a ship in 2013, and on Tuesday it is believed to have detonated after a fire broke out nearby.
The 2017 letter from the custom's chief to a judge could not be immediately confirmed, but state prosecutor Ghassan Oueidat ordered security agencies to start an immediate investigation into all letters related to the materials stored at the port as well as lists of people in charge of maintenance, storage and protection of the hangar.
In the letter, the customs chief warns of the "dangers if the materials remain where they are, affecting the safety of (port) employees" and asked the judge for guidance on what to do with it. He said five similar letters were sent in 2014, 2015 and 2016. The letter proposes the material be exported or sold to a Lebanese explosives company. It is not known if there was ever a response.
President Michael Aoun vowed before a Cabinet meeting on Wednesday that the investigation would be transparent and that those responsible will be punished.
"There are no words to describe the catastrophe that hit Beirut last night," he said.
After the meeting, the Cabinet ordered an unspecified number of Beirut port officials put under house arrest pending the investigation and declared a two-week state of emergency, effectively giving the military full powers during this time.
The government also said public schools and some hotels will be opened for the homeless and promised unspecified compensation for the victims.
With the Port of Beirut destroyed, the government said imports and exports will be secured through other ports in the country, mostly in the northern city of Tripoli and the southern port city of Tyre.
There were signs that public anger went beyond port officials to the country's long-entrenched ruling class. Political factions have divvied up control of Lebanon's public institutions, including the port, using them to benefit their supporters, with little actual development. That has translated into crumbling infrastructure, power outages and poor services.
"May the Virgin Mary destroy them and their families," Joseph Qiyameh, a 79-year-old grocery store owner, said of the political leadership. The blast damaged his store, injuring his arm, and his wife — at home next door — was hospitalized with injuries. He doesn't have the money to fix his business, with his savings locked up in banks by capital controls imposed during the crisis.
A small protest broke out after former Prime Minister Saad Hariri made a public appearance Wednesday, with people chanting slogans against politicians. Fistfights broke out between Hariri's supporters and protesters. Hariri resigned in October amid nationwide protests.
Residents of Beirut confronted a scene of utter devastation Wednesday. Smoke still rose from the port. The blast knocked out a crater some 200 meters (yards) across that filled with seawater — it was as if the sea had taken a bite out of the port, swallowing buildings with it. Much of downtown was littered with damaged vehicles and debris.
Lebanon was already on the brink of collapse amid a severe economic crisis. Many have lost their jobs and seen their savings evaporate because of a currency crisis. Food security is a worry, since Lebanon imports nearly all its vital goods and its main port is devastated. The government is strapped for cash.
Drone footage shot Wednesday by The Associated Press showed the blast tore open the silo building, dumping its contents into the debris and earth thrown up by the blast. Estimates suggest some 85% of the country's grain was stored at the now-wrecked silos.
Economy and Trade Minister Raoul Nehme said all the wheat stored there was contaminated and unusable. But he insisted Lebanon had enough wheat for its immediate needs and would import more, according to the state news agency.
In the Netherlands, a U.N.-backed tribunal postponed delivery of judgments in the trial of four members of the militant group Hezbollah charged with involvement in the 2005 assassination of former Lebanese prime minister Rafik Hariri.
The verdicts were moved from Friday to Aug. 18 out of respect for the victims of the blast, the court said.
Emergency aid was starting to filter in. Two planeloads of French rescue workers and aid headed to Beirut and French President Emmanuel Macron was to arrive Thursday to offer support. Lebanon is a former French protectorate and the countries retain close political and economic ties.
Several jets from Greece, Kuwait, Qatar and elsewhere carrying medical equipment and supplies arrived at Beirut's international airport. Turkey was sending search and rescue teams, humanitarian aid, medical equipment and a field hospital, its Foreign Ministry said. The EU planned to send firefighters with vehicles, sniffer dogs and equipment designed to find people trapped in urban areas.
