Anatomy of a Bomb: An Inexpensive and Deadly Mishmash of Ingredients

It wasn't sophisticated, but it would have done a lot of damage. The car bomb that failed to explode in Times Square Saturday night was composed of easy-to-use and easy-to-obtain ingredients that can be bought for less than $300 and assembled in a few hours with the help of easy-to-follow instructions that are readily available online.

The mishmash of everyday objects from the kitchen to the garden, including a mess of wires, firecrackers, propane, gasoline and basic cookware, is making some heads scratch. Investigators are still working out how it was designed to work, and whether it even could have worked at all.

Sources told FoxNews.com that investigators have a working theory: that the bomb was actually made up of four separate individual explosive components — essentially, four bombs comprising one big bomb inside a 1993 dark green Nissan Pathfinder. The idea was that a sugar nitrate compound in the back of the car would act like ammonium nitrate-based fertilizer, which was used in the deadly Oklahoma City bombing 15 years ago.

Under this theory, the firecrackers would have started the process by setting off triggering devices attached to cans of gasoline sitting in the back seat. That would have created an explosion that would then have set off the sugar nitrate compound and propane tanks.

Multiple police sources suggested that the cell phone and wristwatch recovered from inside the vehicle may have been intended to be used as separate timing/triggering devices.

The hodgepodge of materials inside the SUV:

-- In the back seat: A 16-ounce can packed with 20 to 30 M-88 firecrackers -- available legally in many states -- in between two full 5-gallon gasoline containers.

-- On the floor of the back seat: two cheap-looking yellow travel alarm clocks with wires connected to the bucket of firecrackers.

-- In the trunk: A 55-by-32-inch gun locker filled with eight bags of non-explosive grade fertilizer totaling about 100 pounds (available at any gardening store); a metal pressure-cooker type of pot (available at any department store) stuffed with “a bird's nest” of even more wires and firecrackers.

-- Also in the trunk: Three "barbecue-style" propane tanks (available at any outdoor store), and some more firecrackers attached to at least one of the tanks.

At first glance, experts agree there didn't appear to be a high level of sophistication.

But the bomber’s decision to use everyday components available for purchase in any hardware, grocery or home improvement store shows a certain savvy, they said.

Since 2001, it’s become difficult to purchase bomb components without setting off red flags. For example, store owners are told to be on the lookout for any beauty supply shopper buying huge amounts of peroxide. There are regulations that limit the amount of other products that could be used to assemble an explosive device.

So by sticking to Home Depot or Lowe’s or hardware or grocery stores, the would-be Times Square bomber remained off the grid and out of the watchful eye of law enforcement.

“We’ve made it increasingly difficult for people in this county to get high amounts of explosives; we’ve alerted sellers to watch out for unusual purchases of the chemicals involved in fabrication of explosives,” said Brian Jenkins of the Rand Corporation.

“Therefore, as a substitute, there may be a trend that we now see — a trend of terrorists moving in [the] direction of incendiary devices, because components are readily available.”

The bombs also are cheap to build. Mark Novak, president of New York-based Global Security Group, estimated that the bomb could be put together for less than $300.

It would take only an hour or two to assemble with the help of any of the numerous instructional videos on YouTube, online postings, or books by anarchist or terrorist groups that provid step-by-step guidance on assembling homemade bombs.

Police said the fertilizer was the wrong kind — it would not have had the deadly effect of ammonium nitrate. Still, even without the fertilizer, the ignition of gasoline and propane could have cut the car in half and created a huge fireball, New York Police Commissioner Ray Kelly said.

Novak said just because the bomb appears crude and amateurish doesn't mean it wouldn’t have been deadly.

Even though the bomber used the wrong fertilizer, he said, you’d still get a pretty powerful blast that would send a fireball into the air and shrapnel flying.

“You have something that didn’t function as designed, either due to lack of sophistication or malfunction of equipment,” he said.  “The initial explosion failed to ignite the other materials.”

He compared it to what happened to the would-be Christmas Day airline bomber when explosives packed inside his underwear failed to ignite on a Northwest Airlines flight to Detroit.

"If you end up being confused about how this was supposed to work, you’re understanding the situation perfectly. Assuming it was supposed to function, it may end up that the person doesn’t have real grasp of what’s going on,”  said Charles Faddis, a former CIA operations officer who was the head of the CIA's weapons of mass destruction terrorism unit.

“It seems like you got a guy trying hard not to get detected while assembling it and ended up assembling something not very effective.”

But, Novak said, “Whoever did this had the intention to kill a large number of people.”