Just read an article somebody stole 40k from an atm. How is that possible that an atm carries that much? And is it even possible to get inside an ATM if so?

This is what 100k in cash looks like:

It's not that tricky to fit all that in an ATM. ATMs are built to be difficult to remove and get open but with the right tools anything that can be closed can also be opened. The trick is to do that without damaging the bills inside, which I imagine the news wouldn't report on

I used to work for a company in Australia that packed ATMs. A busy ATM stocked with 50s and 20s usually would hold $340k. We also packed some for a casino that held 100s and 50s and they were often packed with $650k.

You'd be surprised how insecure they are (or were) from the non-physical side. Check out Barnaby Jack's talk from DefCon 18 (Jackpotting Automated Teller Machines Redux).

A few years back there was a gang of criminals that used explosives to breach ATMs in the area I live. They had quite the spree, about one a week I recall.

Most of the places just stopped having ATMs. There's less than halve remaining, I'd estimate.

Yes...yeeees... Tell me how to get into one so I can ensure don't accidentally do it...

Some ATMs support deposits. Also it's possible the 40k is not from a physical breach but a skimmer stealing PINs.

I saw a video of people ripping ATMs out with trucks too

Rough math wise and ATM can easily hold $40k. That's 8.6 inches of $20 bills, it might be a mostly full ATM, but a believable amount.

As for how easy it is to break into an ATM, it's not easy, but it's not impossible. They are designed to be serviceable by a single person, so the doors and locks while strong, aren't going to hold up to the force of a vehicle or explosives from someone that knows what they are doing. The hard part is removing the cash box, which depending on the machine it can be easier to take the whole machine. Once you get the machine/box to a second location the security is irrelevant.