HomeABC NationalTimeline: How the shooting at a Texas elementary school unfoldedTimeline: How the shooting at a Texas elementary school unfoldedWed, May 25, 2022 by ABC NewsSHARE NOW Eric Thayer/Bloomberg via Getty Images(UVALDE, Texas) — What began as a milestone marking adulthood ended in tragedy after a suspected gunman used the AR-15 style rifle he purchased days after he turned 18, authorities said.Uvalde High School student Salvador Ramos allegedly purchased two assault rifles just days after turning 18 and used them to carry out the second-worst school shooting in U.S. history — all within a span of eight days, authorities said.Ramos was known for fighting and threatening fellow students, some classmates told ABC News. He allegedly exhibited unusual behavior such as threatening classmates and claiming to have cut scars into his face, classmates said.Authorities said during a press conference Wednesday afternoon that Ramos had dropped out of school.Twenty-one people, including 19 third and fourth grade children, were killed in the attack, law enforcement officials said. Two teachers were killed, too. Another 17 people were wounded, including three law enforcement officers.This is how the shooting unfolded:March 20 Ramos moves in with his 66-year-old grandmother, Celia, Steve McCraw, director of the Texas Department of Public Safety, said during a press conference Wednesday afternoon.May 16 Ramos turns 18, according to the Bureau of Alcohol, Tobacco, Firearms and Explosives.May 17 Ramos buys a semi-automatic rifle at a local sporting goods store called Oasis Outback, McCraw said.May 18 Ramos purchases 375 rounds of ammunition for that rifle, McCraw said. It is not known where he purchased that ammunition.Friday Ramos buys a second semi-automatic rifle at the same store, McCraw said.TuesdayMorning: An Instagram account that law enforcement sources tell ABC News they believe is connected to Ramos sent another user on the social media platform a photo of a gun laying on a bed, according to a user who shared direct messages from the suspect’s alleged account with ABC News.11 a.m.: Ramos allegedly had three communications on the social media platform Meta describes as private one-to-one text messages. One message to an unknown recipient stated that he was going to shoot his grandmother, Texas Gov. Greg Abbott said in a press conference Tuesday.Before 11:30 a.m.: Another one-on-one message said he had shot his grandmother, and the third said he was going to shoot an elementary school, but did not specify the school, Abbott said.Ramos then shot his 66-year-old grandmother in the head at their residence, and she was able to run across the street and call police, McCraw said. She was taken to the hospital via helicopter and is still in critical condition, McCraw said.Ramos drove about 2 miles to Robb Elementary in his grandmother’s truck crashing the vehicle outside the school, McCraw said. He exits the vehicle with a backpack and rifle, authorities said.11:32 a.m.: The gunman went toward the west side of the campus, which is a back door, but as he was approaching the door, a Uvalde Independent School District police officer attempted to confront the gunman him, McCraw said.Ramos shot the school district officer, authorities said.At one point, students heard banging on a window before their teacher saw the shooter with a “big gun,” a fourth-grade student who was inside the school at the time said in an interview with ABC News, describing the “nonstop” gunshots that followed.After Ramos entered the school through a back door, he went into a classroom that was connected internally to a second classroom and began shooting, authorities said.“That’s where the carnage began,” McCraw said.Law enforcement then converged into the classroom and Ramos was shot and killed by an officer, authorities said.11:43 a.m.: Robb Elementary School posts to Facebook that the campus has gone under lockdown “due to gunshots in the area.”12:17 p.m.: Uvalde Consolidated Independent School District announces the shooting on Twitter.12:30 p.m.: Uvalde Fire Department scanner traffic calls on “additional firemen need to respond to Mill Street to establish a perimeter to assist Uvalde EMS and Uvalde PD.”1:06 p.m.: Police report that the suspected shooter was killed by officers at the scene after they broke into the classroom.ABC News’ Lucien Bruggeman and Matthew Fuhrman contributed to this report.Copyright © 2022, ABC Audio. All rights reserved.