While I was based in Germany I was evacuated twice while WW2 bombs were defused, they're often discovered by air survey, the two that I had to move out for were removed about a year apart and there were no restrictions about going on the land where they were even though the council new they were buried there.
Modern bombs aren't really more powerfull but they are more accuratly delivered, still I wouldn't consider 500lb a big bomb
Re-read that article 1100lb, yeah thats pretty big. Wouldn't want a 1lb bomb to hit me, thankfully we usually have the air power.