In 1990 several of us heard a noise from the top of the cabin of a BA 747 as it taxied at San Francisco airport.
It was a bang and then sounded like something was rolling around in for want of a better word the ceiling of the cabin.
The cabin crew were informed and one of them spoke to I presume the flight deck via the intercom. However the plane
just kept going but when it got to the end of the runway, lined up for take off it did it again. The intercom was used again
but the result was we just took off anyway and no announcement was made, all the cabin crew person said was "everything is in order"
There were several other slightly concerned passengers as well as myself but we all felt we had better just shut up and not say anything more.
As we landed it did it again but as we were safe on the ground no-one said a word.