Not true...detonating nukes high up to create EMPs to wreak havoc on electronics and communications but not damage the infrastructure is old school cold war stuff.
It was huge as far as meteors go...blew up from the air pressure in the 30 mega-tonne range. Too high to cause real damage and without the radiation a nuke would bring so...no emp.
Just a big, spectacular chunk of space rock that rightfully scared the crap outta a lot of people.