Nearly four days have passed since four men detonated explosives-laden belts and luggage in the Brussels airport and metro killing nearly two dozen people and injuring hundreds and there’s still quite a bit of ambiguity regarding who exactly is dead, who’s still at large, and who was at the scene in the first place.
Part of the confusion stems from the fact that the attackers who died in the blasts were strewn all over the crime scene in pieces, but authorities did manage to determine that among those who blew themselves up were brothers Khalid and Ibrahim El-Bakraoui, one of which was the subject of an Interpol red notice and the other was flagged by Turkey as a “foreign fighter” and deported. Also thought to have been killed in the airport bombings: bombmaker Najim Laachraoui, who is said to have played an instrumental role in building the explosives used in the Paris attacks.
Following the bombings, the taxi driver who delivered Ibrahim Bakraoui, Laachraoui, and a third assailant to the airport called the police. The driver became suspicious when the men were reluctant to let him assist with their luggage which he described as exceptionally heavy. The driver then led police back to the apartment in Schaerbeek (the site of Friday's sweeping police operation) where he had picked the three men up. On the fifth floor, authorities found 33 lbs of explosives, 180 liters of chemicals, guns, a suitcase full of nails, and an Islamic State flag. Nothing suspicious about that.
Apparently, the apartment was a bomb making factory and in it, the Bakraouis (possibly with the help of Laachraoui or another bombmaker), built the TATP-based explosives used in Tuesday’s attacks. TATP, or triacetone triperoxide, has become an ISIS favorite and for those unlucky enough to find themselves in close proximity when it’s detonated, it’s bad news. Dubbed “the mother of Satan” by Palestinian militants, the white powder is cheap to make and the ingredients are impossible to trace, making it ideal for the clandestine activities of the Islamic State cells operating under the radar of European anti-terror police.
“Used in the 2005 London bombings and the Nov. 13 Paris attacks, and found in a series of foiled bomb attempts in Europe since 2007, TATP appears to be Islamic State's explosive of choice,” Reuters writes. Here’s more:
Making a TATP bomb, although a more lengthy process than the fertilizer-based explosives used by other European militants, is cheap and simple and recipes and videos by chemistry buffs abound on the Internet. It was discovered by a 19th century German chemist and is very powerful, even in small quantities.
All the ingredients - acetone found in cleaning products, hydrogen peroxide found in wood bleach and sulphuric acid used to unblock kitchen pipes - were available at one Brussels hardware store this week for less than 40 euros ($45).
Nails and bolts can be added to increase the bomb's impact and afterwards stuffed into bags and taped into suicide belts.
It goes undetected by airport scanners, leaving authorities to rely on sniffer dogs. Though the bombs can have a strong smell -- the bombers' taxi driver said he smelled chemicals on the ride to the airport -- there were few such dogs in the Brussels' airport check-in area on Tuesday when the men detonated the explosives hidden in holdalls on baggage trolleys, according to several witnesses, including an airport worker.
Ehud Keinan, an Israeli scientist who has spent 35 years studying TATP, said that as little as 4 kg could produce the kind of devastation seen in Brussels.
"It is very easy to make, not like a conventional bomb," said Keinan, the dean of chemistry at Technion-Israel Institute of Technology in Haifa.
"You don't need to be part of a large organization or need training to do this."
Still, one of the three Brussels suspects, Najim Laachraoui, a 25-year-old Belgian who blew himself up in the airport attack and is suspected of making suicide vests for Paris, had studied engineering at university and excelled in lab work.
Within two weeks of the July 2005 London attacks, the British chemical industry and British hardware stores stepped up their reporting of suspicious or large purchases of chemicals.
However, in France, the explosive precursor hydrogen peroxide is sold legally as a way to clean private swimming pool water and no one is considering banning nail varnish remover.
"If you go into any pharmacy in Brussels, you can buy 50 ml of acetone. If you go into a hundred pharmacies, you can get that much more," said Peter Newport, the chief executive of Britain's Chemical Business Association, which sits on the European Commission's expert group on regulating precursors.
“There are actually very few bombmakers in the grand scheme of things,” Brian Castner, a former Air Force explosive ordnance disposal technician and author of the book “All the Ways We Kill and Die,” tells The Washington Post. “Once one finds a successful way to construct these things, they [can] mass produce.”
"While there are bomb-building manuals available on the Internet, Castner added that a competent terrorist cell would not rely on them; instead, recruits apprentice with master bombmakers in places such as Syria and Iraq before returning to their home countries," WaPo continues. "And in Afghanistan and Iraq, the United States has targeted bombmakers."
For the scientifically inclined, here's a detailed description of "mother of Satan" from Tech Insider:
One reason TATP is difficult to detect is because it does not contain nitrogen, a key component of homemade "fertilizer" bombs that security scanners are now very good at finding.
Each molecule contains only hydrogen, oxygen, and carbon — some of the most common elements on Earth — shaped in a ring.
The explosive power of TATP has puzzled scientists since its discovery in 1895. Unlike nitrogen-based bomb materials, which store up energy as they're cooked into explosive form, TATP can be made at room temperature — no flames required.
So where does it get its explosive energy, if not by heating?
It wasn't until 2005 that Keinan figured out detonating TATP is more like a massive air blast than a fire bomb. When a crystal of the explosive is rattled hard enough, each solid molecule instantly breaks into four gas molecules.
"Although the gas is at room temperature, it has the same density as the solid, and four times as many molecules, so it has 200 times the pressure of the surrounding air," according to the release about Keinan and his colleagues' 2005 study of TATP.
"This enormous pressure — one-[and-a-half] tons per square inch — then pushes outward, creating an explosive force" on par with TNT, states the release.
"In a TATP explosion, the gas molecules give up their energy of motion to the surroundings, in the process creating the shock wave that does the damage."
So an extremely powerful (if unstable) explosive powder that's easily synthesized from cheap, readily available, not to mention completely legal ingredients. "There are so many valid uses by the public of these substances," the aforementioned Peter Newport admits. Right, but there aren't a lot of uses for 40 gallons of acetone and eight gallons of hydrogen peroxide (the quantities found in the Schaerbeek hideout) and as The New York Times notes, US officials are curious as to "how the terrorists were able to elude detection" while obtaining those quantities of precursors - "especially during a manhunt for Salah Abdeslam."
The answer, of course, is that Belgian authorities have proven themselves to be completely incompetent and, as we wrote earlier today, have now simply resorted to arresting people first and asking questions later in an increasingly desperate attempt to get out ahead of the next attack which we imagine was probably planned weeks ago in a Molenbeek apartment amongst empty bottles of nail polish remover, loaded Kalashnikovs, and half-empty pizza boxes.
As for the public, we implore you to do your part by following the advice that's prominently displayed on signs plastered all over New York's Grand Central Station: "If you see something, say something." In this context we suppose that means that if you see the guy shown below buying a bottle of nail polish remover (or worse, a can of Nutella), call the police immediately...