But during the nearly two hours after the initial call, parents had little hesitation to rush over to the campus, while also getting few answers from law enforcement at the scene. After all, the Robb Elementary tragedy in Uvalde was still a recent event that has borne criticism over emergency responses.
[Ads /]
Parents crowded behind police tape that kept them from getting to students, who were kept locked indoors out of precaution, hoping that, unlike in Uvalde, that there wouldn't be any reason to break through the line and go after their kids.
SEE MORE: 'There was no active shooter' at Heights High School, says Houston police chief
Ripping gun laws
One parent had the benefit of hearing from his son, a Heights junior, as well as a friend in law enforcement despite what little info was being given to parents at the scene.
"I've always told him, if there's an active shooter, get out the building. You don't want to be a sitting duck," Anthony Messa, a Heights High parent, told ABC13, adding that the lockdown prevented any escape.
Messa, though, expressed numbness over the thought of a school shooting, ripping current gun laws out of Austin.
"I think most people are numb to the situation. It's happening every week. People are probably getting numb to the whole situation. What do they expect when they change the gun laws? (They) made it the wild west again. Anybody can get a gun at anytime," Messa said while expressing that he wasn't shocked to hear about a threat. "To me, it all comes down to those gun laws. It's just a byproduct from those gun laws. It's a free for all, pretty much. No background checks. You don't have to be 21. Anybody can get a gun right now."
SEE MORE: What to know about 'constitutional carry' now that it's in effect
Heart-sinking feelings
[Ads /]
Other parents had heavier priorities in mind beyond politics.
An unnamed woman who was interviewed live on ABC13 nearly broke out in tears over the uncertainty of her two students' safety.
"My heart just dropped. There's nothing you can say. You feel the worst. You see the worst. It's just hard. This is hard," she said.
She was able to hear from her junior student, whom she said had to use a friend's phone to text her because data was being tied up.
Another mom, who came all the way from Humble, took the communication to task, adding that she was outside of the school for an hour and a half before she got anything from officials.
"He called and said, 'Mom, come get me ... They were telling us to stay put, stay quiet.' I was scared after what happened in Uvalde," the woman said before voicing homeschooling as a possibility for her child.
[Ads /]
One more mom, who rushed over from Washington Avenue, had not just Uvalde in mind, but an incident from the year before as a reason for being there when she did.
"It's chaos. They had an incident before last year here where the student had a gun in the parking lot," Queda Daniels, a mom to a 17-year-old student, said. "I'm not trying to take no chances."
SEE MORE: Heights HS locked down after student shot in parking lot, school tells parents
How HPD explained the silence in wake of threat
Ultimately, the lack of communication for over an hour appears to be the overwhelming highlight of an incident that had no deaths or injuries.
Houston Police Chief Troy Finner sympathize with eager and anxious parents but stressed the need to search and clear the scene to assess the appropriate response in the event tragedy did happened.
"I'm a parent. I got a kid in HISD. But we got to use some kind of reason here. We have to search the school. That is the most important thing: to stop the threat if there is a threat. We don't have time to call. Once we make it safe, we start making those calls," Finner said.
WATCH: Panicked parents show up at Heights HS in wake of threat
Heights HS parents rail against HPD, gun laws in wake of school threat