Updated: 1:23 p.m. ET
The CBS Evening News, NBC Nightly News
and ABC World News will again expand to an hour on Friday to cover the continuing story of a
manhunt underway in Boston for the second marathon bombing suspect.
One suspect was killed in a shootout early Friday morning
and police are searching for his brother, 19-year-old Dzhokhar Tsarnaev. The
broadcast and cable news networks have
been in continuous coverage of the breaking story since Friday morning.
Scott Pelley will also anchor an hour-long primetime CBS
News special at 9 p.m., pre-empting Vegas which will now air Saturday at 8 p.m., and NBC's Rock Center with Brian Williams will
devote its full live hour at 10 p.m. to the investigation. ABC's Elizabeth Vargas will anchor 20/20 from Boston and Juju Chang will be live from the city for Nightline.