Here is a horary interpretation for the question. And below that is the event chart. Both showing similar testimonies.
Beirut, being in a foreign country for the querent, is Venus, L9.
Venus’ last aspect was with the Moon, the ruler of radical L6. We already have an indication of an accident.
Saturn is the turned L4, that is “the port facility” where the Ammonium Nitrate was stored. Saturn also is the natural ruler of storage and security. It is in its own sign but retrograde so the storage is not secure enough. Saturn closely squares the 9th cusp.
Inside the turned house 4 we find Jupiter, the natural ruler of things that expand. An apt significator for the Ammonium Nitrate stored in the facility. Jupiter is under the “care” of a retrograde Saturn, so unsafely stored.
The last aspect with Saturn was an opposition from Mercury, the turned 12th ruler from, the 9th and also the turned 12th ruler from the 10th from the 9th. A self-harming error by the authorities in that city.
What kind of error?
Mercury is ruled by the Moon (radical L6) and by Jupiter (turned L6 from the 9th) by exaltation. A house 6 type of error.
Venus is ruled by Mercury. That is, ruled by that self-harming error or negligence. Mercury’s antiscion on the star Alcyone is aptly descriptive of the outcome of such error.
Venus is conjunct the North Node. Too bad, in this context. It expanded in a very undesirable way.
Neptune is on the 2nd cusp (turned 6th from the 9th). An unpredictable unseen earthshaking accident. Jupiter tightly sextiles Mars. Mars exalts an angular Sun. We have the picture of an explosion triggered by much heat – fire.
Icing on the cake: Algol, the star of “losing one’s mind” is on the radical 4th cusp; aptly showing the place where Venus’ mind failed: storing a huge amount of an explosive substance in the middle of a city. It does not get any more Algol than that…
Event chart for the place and time of the explosion.
Saturn, the ascendant ruler, is retrograde. Again, same testimony as the horary.
Jupiter, L12 is inside the ascendant, again, as the horary, bringing house 12 to the forefront. Jupiter is squared by Mars, again, highlighting the Martial nature of the event.
The nodes are near the 6-12 cusp axis highlighting those houses.
Saturn is in an opposition with Mercury, L6
Mercury’s last aspect was with Jupiter, linking house 6 to house 12.
Venus, L4, is inside the 6th cusp.
The Moon opposing the Sun, L8, aptly describes the significant loos of life in the event.
Both charts tell me this accident was due to faulty safety measures and was brought on to themselves, by the people responsible for storing and securing a place filled with such an explosive substance.
If it wasn’t for solid the house 6 presence in both charts one might consider reading L12 as a hidden enemy. So, I see no enemies in this chart, except for being one’s own enemy. This was not due to an attack. It was due to naiveté and idiocy.
I also I did a single-card Tarot reading asking for confirmation or correction of the astrological interpretations. It confirms house 12 as self-inflicted harm and thus the astrological answer.
The king of Wands can be (context) one of the several available symbols of self-undoing in Tarot.
Notice the guy is spearing his own heel.