HIGHLANDS RANCH, Colo. –Colorado authorities arrested a 16-year-old girl and an 18-year-old man in a deadly shooting Tuesday at a public school in suburban Denver.

Investigators said one student died and eight others were injured when senior Devon Erickson and younger student Alec McKinney allegedly opened fire at STEM School Highlands Ranch Tuesday afternoon.

We’re continuing to follow any new developments in the shooting. WATCH LIVE on Channel 2 Action News at 5  and 6

The public charter school has 1,850 students in kindergarten through 12th grade.

Here are the latest updates: 

Update 7:30 p.m. EDT May 9: Colorado investigators said school shooting suspects Devon Erickson, 18, and Alec McKinney, 16, tried to set Erickson’s parents’ house on fire before heading to the STEM School Highlands Ranch

Tuesday where they allegedly opened fire on classmates, killing one and injuring eight others, according to KWGN-TV.

Authorities said they found fire accelerants inside the house, but that the blaze caused little damage.

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BREAKING: Both suspects in the STEM School shooting tried to set fire to the older suspect’s home before the shooting, according to sources.

Both Erickson and McKinney are STEM School students. and both have court appearances scheduled for Friday.  McKinney is a juvenile, but Erickson is facing charges as an adult.  He’s facing 30 counts, including one count of first-

degree murder and 29 counts of attempted first-degree murder.

Update 12:05 a.m. EDT May 8: The two suspects accused in the mass shooting at STEM School Highlands Ranch made their first court appearance Wednesday, according to CNN.  Neither Devon Erickson, 18, or Alec McKinney,

16, were formally charged, CNN reported. Both are due back in court on Friday.  The news network, citing anonymous sources, said Erickson took both weapons used in the shooting from his parents and that both were bought

legally.

Update 12:40 p.m. EDT May 8: A classmate of Castillo’s told NBC’s “Today” show that the student killed in Tuesday’s shooting, identified as 18-year-old Kendrick Castillo, lunged at one of the shooters Tuesday, likely saving

lives.

Nui Giasolli, a student at STEM School Highlands Ranch told “Today” her classmate, 18-year-old Devon Erickson, came into class late on Tuesday and pulled out a gun.

“That’s when Kendrick lunged at him and he shot Kendrick,” Giasolli said. His actions gave students “enough time to get underneath our desks, to get ourselves safe and to run across the room to escape.”

Giasolli told “Today” that other students also helped Castillo to tackle the shooter. They “were brave enough to bring him down so that all of us could escape and all of us could be reunited with our families.”

“I can’t thank them enough,” she said.

Update 12:30 p.m. EDT May 8: Douglas County Coroner Jill Roman identified the student slain in Tuesday’s shooting as Kendrick Ray Castillo, 18.

Douglas County Sheriff Tony Spurlock said Castillo was set to graduate in just days.

A classmate of Castillo’s told NBC’s “Today” show that he lunged at one of the shooters Tuesday, likely saving lives.

“Kendrick Castillo was three days from graduation. He loved robotics,” U.S. Sen. Chris Murphy, D-Conn., said in a statement posted on Twitter. “Yesterday, he ran toward the shooter to save his classmates. Read his story, learn his name and do not become numb to this senseless violence.”