I saw video of it. It appeared to start as a small exterior fire and very quickly spread up in side than blew out windows and started the inside on fire. Very quickly the entire 27 floors were fully involved.
I suspect there will be fatalities, and there are reports of people still trapped in portions of the building.
There are questions about the external “cladding” as possibly being responsible for the extremely rapid spread...that may go along with what you saw.