I watched this sci-fi when i was about seven sometime around 1964. It started I think in a diner on an old deserted road in what looked like Arizona. There were teenagers dancing to some music. It was an old classic 60s tune. So while they are dancing something crashes through the roof, and hits a man standing at the counter. He seems to have been killed then comes back to life and starts to attack the other customers. The only other thing I can remember about it was that the Blob-like creatures infested the local power plants and took over by stealth. Can't remember the end. I do remember that it scared the hell out of me.
I wonder if this was the movie version of "Quatermass II". It dates from the late 50s and has a scene where Quatermass is attempting to convice a sceptical group of locals about the goings-on at the local factory when a meteorite crashes through the ceiling and injures the barmaid, proving his point. The alien creature is a giant blob and it is contained in something resembling a power station. Hope that helps!