The Socorro Independent School District stands behind its decision to simulate an act of terrorism without warning teachers, parents or students.

At 8:30 a.m. Tuesday morning, the students and teachers at Eastlake High School were told to vacate the hallways and lock down in their classrooms. According to students and parents, gunshots and screams were heard. The SWAT team was seen entering the school.

Stephanie Belcher has a 15-year-old son enrolled in Eastlake. She said she got a text message from her son that scared her.

"He said, 'I'm not kidding. There's gunshots and people screaming and we were locked in a storage closet,'" Belcher said.

SISD's Assistant Superintendent, Pat O'Neill, said the fact that only the principal of the school was warned was a necessary part of the plan.

"It's an active shooter drill," O'Neill said. "We do this every now and then. If you warn too many people then the simulation is not effective."

"These kids thought that their classmates were being killed and that they could be next," Belcher said. "There's no excuse for that."

"I'd rather them be upset with us now instead of something happening and we're not prepared," O'Neill said. "Then people are going to ask questions like, "Why weren't you prepared?'"

"I went to school in California and I don't remember them shaking the building when we had an earthquake drill," Belcher said.

Eastlake freshman Rudy Soto said the drill was too realistic.

"It was pretty scary," Soto said. "Even the teachers got scared."

Soto said he almost experienced a full-blown asthma attack when he heard the gunshots.

O'Neill said the drill was kept away from kids with special needs. He also said that next time the district will try and do a better job of informing parents.

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