What is the fine-grained topic of the following text: Last time we drove down to Shreveport (LA) where they've been making all the movies they used to make in New Orleans (before Katrina), we stopped at a truckstop and there was a photocopied twenty dollar bill taped to the window and someone had written on it 'Denzel was here' and the date and he signed it. Only return the topic.
Denzel Washington's visit to a truckstop in Shreveport, Louisiana.