I couldn’t picture it.

That’s why it’s taken me so long to weigh in about last week’s rape on a SEPTA train during which passengers reportedly recorded the assault instead of contacting authorities or attempting to intervene.

The facts as previously outlined and that made headlines around the world didn’t add up. As sketchy as SEPTA travel can get, I couldn’t wrap my mind around the concept of people on a train knowingly not going to the aid of a fellow passenger who was being raped. As bad as things have gotten in this hard, cruel city, it hasn’t gotten this bad.

That was just a hunch I had.

And it was borne out Thursday when Delaware County District Attorney Jack Stollsteimer held a news conference outside the courthouse in Media and pushed back against that version of events.

“There seems to be this narrative out there that I’ve been getting from constituents and from people that there was a group of people who were callously sitting there filming this incident and didn’t act,” he said. “That wasn’t true. It’s not what happened.”

» READ MORE: Delaware County DA: It is ‘simply not true’ that witnesses took cellphone videos of SEPTA train rape instead of calling police

I figured as much.

I wasn’t there. Nor did I see the video, but Stollsteimer said some of the passengers riding on the westbound train from the city around 10 p.m. on Oct. 13 might not have even been aware that an assault was transpiring.

It makes sense. They might have had their heads down and been engrossed in their phones. Or else they may have glanced over and seen the alleged assailant on top of the partially disrobed victim and chalked it up to late-night transit shenanigans. If you’ve ever ridden certain lines at night, you know the kind of aberrant behavior I’m talking about.

One reason Stollsteimer spoke out is that he needs potential witnesses to come forward. As he pointed out Thursday, “It’s not necessarily true that any one person getting on the train is going to know exactly what was going on, which is why we’re trying to gather everyone’s evidence if they are a witness to this.”

“I just want to get the narrative out there to folks that there is no reason to think that there are these large groups of people who for their own gratification videotaped this and just watched it happen,” Stollsteimer added. “That’s simply not what happened.”

I was so relieved to hear him say that.

We’re not so callous as to stand by and let something like that just happen without trying in at least a small way to help.

And in fact there are people who didn’t sit still. Like the off-duty SEPTA employee who notified authorities about the alleged attack.

And like SEPTA Police Officer Tom Schiliro, who along with his partner arrested the accused rapist, Fiston Ngoy, 35, after the train pulled into the 69th Street stop in Upper Darby. He told me other passengers readily pointed officers toward the suspect, who still had his pants down and was on top of the victim.

“As soon as the train cars opened, everyone was pointing, ’It’s over there! It’s over there,’” Schiliro recalled.

So, the passengers that night might not have gotten physically involved, but they weren’t as callous or as indifferent as they had been portrayed.

» READ MORE: Tips for how and when to intervene if you witness an emergency like last week’s rape on SEPTA

It’s reassuring to know that there are still good people among us who are willing to act.

Then there was the Good Samaritan who rushed to the aid of another female SEPTA passenger at the 69th Street terminal this past Wednesday night. The woman had asked a 28-year-old man about getting to the other side of the tracks when he offered to accompany her — only to begin tugging at her clothing and pulling his own pants down.

Schiliro happened to be nearby, heard her cries, and immediately rushed over. He spotted the partially disrobed assailant and immediately arrested him.

That’s two sexual-assault arrests in less than a week. You can’t tell me he isn’t a hero. Same thing with the unnamed Good Samaritan who came to the victim’s aid.

People are so quick to believe the worst about humanity. And ignore the good among us.