Go to the Chemicack shop, and use all topics of conversation. When he's gone, interact with the desk to find a note. Open your inventory and look at the note. Go back to the map and go to the apartments.

Find the right apartment of Weyland Smithey and look at the letterbox. Go back to the crash site.

Pick up the metal bar. Go back to the apartments.

Use the metal bar on the letterbox. Enter the room.

Look at the three large posters. Exit the room.

Go to the bus depot via the map.