An 18-year-old student was killed and a 17-year-old student was injured after a model rocket exploded Monday night at an elementary school in Southern California.

Witnesses told NBC4 both victims are high school students from Thousand Oaks and were testing out a rocket project when things went awry.

The man killed was identified by the Ventura County coroner Tuesday as Bernard Moon.

The explosion was reported at 7:35 p.m. at Madrona Elementary, located in the 600 block of Camino Manzanas, according to Capt. Mike Lindberry of the Ventura County Fire Department.

Witnesses said the explosion was so loud, they thought it was a "sonic boom."

"From all accounts, they didn't try to launch their rocket. Something went terribly wrong and the one boy was holding it, and it exploded," said Tammy Coburn, a witness who heard the explosion.

The two students were transported to the hospital, one in critical condition and the other in stable condition, according to Lindberry.

The Ventura County Sheriff's Department later confirmed the 18-year-old student had died.

Authorities did not publicly identify the students involved.

Initially, authorities would only say an adult was killed and a juvenile was injured, but later revealed the students' ages.