The Understanding 9/11: A Television News Archive provided by the Internet Archive contains about 3,000 hours of September 11, 2001 television coverage from 2O channels (U.S. and international). All video can be streamed online. This is a free resource.
The website also contains materials from the 9/11 TV News Archive Conference held on August 24, 2011.
See Also: The Internet Archive’s “Archive-It” service and the National September 11 Memorial Museum provides access to a keyword searchable database of 9/11 web content