The Tampa Bay Rays felt a "palpable" need to act after 19 students and 2 teachers were murdered in Texas. The Yankees agreed.

11:35 a.m. A total of seven officers enter the building. The gunman fires through the closed door, gracing two officers. They are forced to withdraw. 11:37 a.m. Within the space of a few minutes, the gunman fires an estimated 16 rounds.

12:03 p.m. The first 911 call from inside the school is received from a female child in Room 112. The call lasts 1 minute, 23 seconds. From 12:10 to 12:47, at least four more calls are made to 911. The child in Room 112 asks 911 "to please send police now."

12:50 p.m. Officers open the door using keys obtained from a janitor. It's believed the gunman locked the door. Officers enter and kill the gunman. Shots are heard in the 911 call.

Read the full story: USA TODAY is providing details about the shooting to inform how mass attacks are planned and carried out. These details give authorities and the public information that could help spot future mass shooters and even prevent them.

Experts said many Americans need to take these warning signs more seriously, while also avoiding profiling groups of people.

“People get traumatized individually but we heal as a community." A crisis counselor who worked with Sandy Hook Elementary School said a mass shooting should never be forgotten, but there is a chance for healing.

Man pleads guilty in plot to firebomb California Democratic HQ after Donald Trump lost 2020 election.

Seventy-nine minutes passed between the time the gunman began firing outside Robb Elementary School and the moment police shot him dead. While police failed to act, 10-year-olds and their teachers were making frantic calls to 9-1-1.