Stopping for directions at a Freeway.

First car accident. I'm a safe driver and keep my distance and all that. Today, I was on my way to return my car rental, naturally looking up to read the signs denoting which lane to keep for rentals, departures etc. All of a sudden, I (Car C) rear end a car (Car B), which hits another (Car A) in front of it.

Long story short, this happened in a freeway with a 55mph speed limit. Both Car A and B had stopped completely, and Car B driver was inside Car A apparently getting directions. The parties did not claim to know one another. Car B had no one inside at the time of collision. As mentioned, I do keep my distance, but as a driver, we assume the vehicle in front is also moving. That was my mistake. Sure, I saw Car B up ahead and thought "OK I have a couple seconds (assumed Car B was also in motion) to look up and read the airport signs." At 55mph those seconds were costly. I looked back down and it was already too late. I hit the brakes but that didn't stop the collision.

So I'm sure I'll be at fault. That's not the point of writing this. The point is, it just feels like a set-up. Or just a really unfortunate event. If Car B needed directions, how would they have stopped Car A and hopped inside Car A for said directions when Car A was in front? What are you all's thoughts on this?

Happy to answer any questions if you have them.