Siren confusion

Yesterday one of my coworkers left a little before I did because she was not feeling too well.

When I was leaving the parking lot I heard a fire engine siren in the distance.  As I was waiting at the light to turn left I heard it getting closer but couldnt see it.  The first thing I did see was a police car coming up the road behind me with its lights flashing.  (To which my first thought was "police cars dont make that sound" since all I could hear was the fire engine's siren)  Then, as I glanced left I saw the fire truck flying south on Barbur.  By this time the police car had reached the intersection as well and turned right to speed off after the fire engine.  The next thoughts flew through my head in less than a second:

I hope everyone is okay.

Lord, please help everyone to be okay.

I hope my coworker is not involved (That is the way she goes to get home).  

Later I texted her and found out she made it home and was even feeling a little better.