Kixxo

Hi, I'm new to this forum and Cities Skylines. I'm into my first city in the shady strands map. I've gotten some helpful assets from the forum here, but I've had a problem deleting assets that have tunnels. When I bulldoze them, it leaves behind a remnant where the tunnel's exit and entrance were. It's the little T icon that gets left. Here is a screenshot below Iw this a bug or is there a way to delete them? Thanks