2020 Beirut explosion
On 4 August 2020, a major explosion occurred in Beirut, Lebanon, triggered by the ignition of 2,750 tonnes of ammonium nitrate. The chemical, confiscated in 2014 from the cargo ship and stored at the Port of Beirut without adequate safety measures for six years, detonated after a fire broke out in a nearby warehouse. The explosion resulted in at least 218 fatalities, 7,000 injuries, and approximately 300,000 displaced individuals, alongside property damage estimated at US$15 billion. The blast released energy comparable to 1.1 kilotons of TNT, ranking it among the most powerful non-nuclear explosions ever recorded and the largest single detonation of ammonium nitrate.
The explosion generated a seismic event measuring 3.3 in magnitude, as reported by the United States Geological Survey. Its effects were felt in Lebanon and neighbouring regions, including Syria, Israel, and Cyprus, over away. Scientific studies noted that the shockwave temporarily disrupted Earth's ionosphere. Adjacent grain silos at the Port of Beirut sustained major damage. Portions of the silos collapsed in July and August 2022 following fires caused by remaining grain stocks.
The Lebanese government declared a two-week state of emergency in response to the disaster. Protests, which had been ongoing since 2019, grew in scale, leading to the resignation of Prime Minister Hassan Diab and his cabinet on 10 August 2020. Claims surfaced suggesting Hezbollah's possible connection to the explosion, citing unverified reports of weapons stored at the site. Hezbollah denied the allegations but participated in demonstrations opposing the official investigation. In late 2025 Israeli reports linked Hezbollah not only to the explosion but also to assassinations by Unit 121 targeting Lebanese individuals that linked the organization to the explosion.
Background
The economy of Lebanon was in a state of crisis before the explosion, with the government having defaulted on debt, the Lebanese pound plunging, and a poverty rate that had risen past 50%. In addition, the COVID-19 pandemic had overwhelmed many of the country's hospitals, several of which were already short of medical supplies and unable to pay staff due to the financial crisis. The morning before the explosion, the head of the Rafik Hariri University Hospital, which served as the main COVID-19 medical facility in Lebanon, warned that it was approaching full capacity.The government-owned Port of Beirut serves as the main maritime entry point into Lebanon and a vital piece of infrastructure for the importation of scarce goods. The Beirut Naval Base is a part of the port. The port included four basins, 16 quays, twelve warehouses, a large container terminal, and a grain elevator with a total capacity of 120,000 tonnes that served as a strategic reserve of cereals for the country. The grain elevator was built in the 1960s as part of an expansion plan advanced by Palestinian banker Yousef Beidas.
Iran's involvement
is a senior official within Iran's Islamic Revolutionary Guard Corps, specifically associated with Unit 190, a division responsible for clandestine arms transfers and logistical operations. He has been implicated in arms smuggling, money laundering, and oil trafficking on behalf of the IRGC Quds Force. Reports indicate that since 2011, the Iranian shipping company Liner Transport Kish, managed by Shahriyari and Mojtaba Mousavi Tabar, delivered significant quantities of ammonium nitrate to Hezbollah. Between 2011 and 2014, multiple shipments were sent to Beirut, including a consignment transported aboard the MV Rhosus vessel in August 2013, carrying approximately 2,750 tons of ammonium nitrate. This shipment was seized and stored in the port, where it remained until its detonation in 2020, causing widespread casualties and destruction.MV ''Rhosus''
On 27 September 2013, the Moldovan-flagged cargo ship set sail from Batumi, Georgia, to Beira, Mozambique, carrying of ammonium nitrate. Rhosus was owned by a company based in Panama but was regarded by the captain as under the de facto ownership of Russian businessman Igor Grechushkin. The shipment had been ordered by an African explosives manufacturing company for mining in Mozambique. However, reporting by Der Spiegel has found that it was not Grechushkin who owned Rhosus, but rather Cypriot businessman Charalambos Manoli, who maintained a relationship with the bank used by Hezbollah in Lebanon.On 21 November 2013, the ship made port in Beirut. Some sources said it was forced to port due to mechanical issues and possibly engine problems, while other sources claimed the owner did not have sufficient funds to pay tolls for the Suez Canal and attempted to take on a shipment of heavy machinery in Beirut. The heavy machinery was stacked on top of the doors to the cargo space containing the ammonium nitrate, causing the doors to buckle, which damaged the ship. After inspection by port state control, Rhosus was deemed unseaworthy, and was forbidden to set sail. Eight Ukrainians and one Russian were aboard, and with the help of the Ukrainian consul, five Ukrainians were repatriated, leaving four crew members to care for the ship.
Grechushkin reportedly went bankrupt, and after the charterers lost interest in the cargo he abandoned Rhosus. The ship soon ran out of provisions, and the remaining crew were unable to disembark due to immigration restrictions. According to Lloyd's List, port state control seized Rhosus on 4February 2014 due to US$100,000 in unpaid bills. The ship had accrued port fees and been fined for refusing cargo. Lawyers argued for the crew's repatriation on compassionate grounds because of the danger posed by the cargo still aboard the ship, and an Urgent Matters judge in Beirut allowed them to return home. They had been forced to live aboard the ship for about a year.
By order of the judge, Rhosuss cargo was brought ashore in 2014 and placed in Warehouse 12 at the port, where it remained for the next six years. Rhosus sank in the harbor in February 2018.
Lebanese customs officials had sent letters to judges requesting a resolution to the issue of the confiscated cargo, proposing that the ammonium nitrate be either exported, given to the Lebanese Armed Forces or sold to the private Lebanese Explosives Company. Letters had been sent on 27 June and 5 December 2014, 6 May 2015, 20 May and 13 October 2016, and 27 October 2017. One of the letters sent in 2016 noted that judges had not replied to previous requests, and pleaded:
Each time, the requests were procedurally declined due to errors by the customs officials. However, the officials persisted in making the same requests instead of correcting the errors. Legal experts also said that the customs officials could have confiscated the material unilaterally.
Explosion
Fire and first explosion
Around 17:45 local time on 4 August 2020, a fire broke out in Warehouse 12 at the Port of Beirut. Warehouse 12, which was waterside and adjacent to the grain elevator, stored the ammonium nitrate that had been confiscated from Rhosus alongside a stash of fireworks. Around 17:55 local time, a team of nine firefighters and one paramedic, known as Platoon 5, was dispatched to fight the fire. On arrival the fire crew reported over the radio that there was "something wrong" as the fire was immense and produced "a crazy sound."The initial explosion, at about 18:07 local time, likely triggered by the stored fireworks, created a large plume of grey smoke and bright firework flashes, and heavily damaged Warehouse 12 with a force equivalent to around 1.5–2.5 tons of TNT.
Second explosion
The second explosion, 33 to 35 seconds later, was far more substantial and felt in northern Israel and in Cyprus, away. It rocked central Beirut and created a large red-orange cloud, briefly ringed by a white condensation cloud. The red-orange colour of the smoke from the second explosion was caused by nitrogen dioxide, a byproduct of ammonium nitrate decomposition.By the next morning, the main fire that led to the explosion had been extinguished.
Yield
Despite inefficient transmission of the shock waves into the ground, the United States Geological Survey measured the event as a 3.3 local magnitude earthquake, while the Jordan Seismological Observatory reported that it was equivalent to a 4.5 earthquake. A study of seismic signatures of the explosion by the Federal Institute for Geosciences and Natural Resources in Germany produced a yield estimate between 0.5 and 1.1 kt of TNT. Experts from the Blast and Impact Research Group at the University of Sheffield estimated that the explosion was one of the largest artificial non-nuclear explosions ever recorded. Later, they were able to quantitatively support this rapid estimate as they compiled more distance versus time of arrival data as new videos of the explosion became available on social media platforms. Their study found that the best estimate and upper bound prediction of the yield of the explosion are 0.5 and 1.12 kt of TNT, respectively. This is equal to around 1 GWh of energy. Another study used several videos of the explosion to describe the evolution of the fireball size and estimated the Beirut explosion yield to be 0.6 ± 0.3 kt of TNT. The Beirut explosion was similar to explosions of large amounts of ammonium nitrate in Texas City, United States, in 1947; in Toulouse, France, in 2001; and Tianjin, China, in 2015.An independent estimate by the International Monitoring System of the Comprehensive Nuclear-Test-Ban Treaty Organization based on infrasonic data obtained an explosive yield equivalent to 0.5–1.1 kt of TNT, making it the sixth-largest accidental artificial non-nuclear explosion in human history.
Aouad et al. derived the kinematics of the fireball from publicly available videos. Considering a time of separation between the fireball and the shock wave at about 170 milliseconds, they concluded a TNT equivalent mass of 0.2 ± 0.08 kt of TNT or 520 ± 200 tons of ammonium nitrate at a distance of 130 meters from the explosion center. This result is consistent with Dewey 2021 that suggests that the Beirut explosion TNT equivalence is an increasing function of distance.
Temsah et al. 2021 estimated the magnitude of the explosion. The research was based on a structural engineering approach with numerical non-linear finite element modelling of the grain elevator facing Warehouse 12 where the explosion took place. The numerical study model was based on silos data and the use of the Conventional Weapons Effects Blast Loading, and the Coupled Eulerian-Lagrangian methods to generate the blast load. The analysis results proved that an amount equivalent to 564 t of AN was adequate to generate damages similar to those resulting from the explosion. This amount represents 20.5% of the original stored amount. As for the state of the grain elevator, results showed it was structurally unstable and should be demolished or properly strengthened.
Kim and Pasyanos put the yield between 0.62–1.25 kt, with the best and most likely estimate at 0.9 kt of TNT, with a likely depth of 2 m.
It has been suggested that not all of the ammonium nitrate was still in the warehouse at the time of the explosion. Some experts estimated that there were only 700 to 1,000 tonnes remaining out of the original 2,750, with the rest having been removed or stolen since 2014. The US Federal Bureau of Investigation estimated there were about 500 tonnes left, a number which was later cited by Prime Minister Hassan Diab. However, there were also two experts who concluded that most or all of the ammonium nitrate exploded.