"Lessee, 1200 lbs over 500 miles wide = 12 lbs per mile in a strip that goes all the way around the world"

I hope you're not a maths teacher Mrrzy!

Still, only a factor of 5 out, it's 2.4lb per mile. That's the good news. The bad news is that the miles don't go all round the world, but over a relatively short distance from the point where hitting the atmosphere makes the satellite disintegrate, to the area where the bits hit the ground. That increases the odds of being hit from zilch to the square root of sod all.