Nashville shooting timeline: How the massacre unfolded at the Covenant School

Three children and three adults were killed in a mass shooting at the Covenant School in Nashville, Tennessee, on Monday.

The alleged shooter, who was identified by police as 28-year-old Nashville resident Audrey Elizabeth Hale, was killed by officers.

Here is the timeline of what took place, according to investigators. All times are local.

9:53 a.m.: The suspect's vehicle is seen on surveillance cameras arriving at the school and parking in the parking lot.

9:57 a.m.: The suspect sends a message on Instagram to a former basketball friend from middle school, where the suspect stated, "I am planning to die today."

10:10 a.m.: The suspect is seen in surveillance footage shooting through the front door and entering the building.

10:13 a.m.: Nashville Police receive the first call of an active shooter inside Covenant School.

10:21 a.m.: The first responding officers arrived on campus, law enforcement officials said.

10:23 a.m..: The first officers enter the school, according to investigators. Police body-worn camera footage shows officers going room-to-room looking for the shooter, clearing classrooms and speeding past at least one body in a hallway.

10:24 a.m..: A team of five officers arrived on the second level and followed the sound of gunfire toward the shooter, according to police body-worn camera footage.

10:25 a.m.: Two officers engaged the suspect, and the suspect is reported down, according to law enforcement officials.

10:27 a.m. The suspected shooter is declared dead, investigators said.