By this time next week, we’ll know which evening newscasts most Americans chose for coverage of the aftermath of the earthquake and tsunami in Japan. As for last week, which included Friday — the day of the quake, “NBC Nightly News with Brian Williams” had a commanding lead.

The broadcast averaged 9.6 million total viewers, +1.3 million more than #2 “World News with Diane Sawyer” and Sawyer had a +2.1 million lead over #3 “CBS Evening News with Katie Couric.” Week-to-Week NBC and CBS were up in total viewers and younger viewers while ABC was down in both categories. ABC News is the only network to have sent its anchor to Japan.

Numbers for the week of March 7:

NBC ABC CBS
• Total Viewers: 9,620,000 8,320,000 6,210,000
• A25-54: 2,970,000 2,290,000 1,850,000