More than a week since a teenager opened fire on young children and teachers at an elementary school in southwest Texas, much remains unknown about why police did not run into the building and what investigators have learned about their response.
Pfizer Inc and partner BioNTech have completed the filing with the U.S. drugs regulator seeking authorization for their COVID-19 vaccine in children under 5 years of age.
A gunman carrying a rifle and a handgun killed four people Wednesday at a Tulsa medical building on a hospital campus, police said, the latest in a series of deadly mass shootings across the country in recent weeks.
