(NewsNation) — As the nation mourns for the Uvalde, Texas, community following the mass school shooting at Robb Elementary School, other school districts across the country have narrowly avoided disasters of their own.

A handful of incidents at schools that could have turned into tragedies were thwarted this week.  

In Texas, five schools went into lockdown Wednesday after reports of an armed person either on or near their campuses. According to officials, the lockdowns were the results of three separate alerts, but nobody was hurt.

Berkner High School and Springride Elementary School in Richardson, Texas, were locked down for almost an hour after police were tipped off about a person holding a rifle and walking near the school near a suburb northeast of Dallas.

“Within minutes of the call being dispatched, numerous police officers from various units within the Richardson Police Department responded to Berkner High School and initiated a search and investigation into this incident,” Richardson police said in a statement.

Authorities identified the suspect as a student of the high school. They found him inside the school without any weapons, but say they discovered what appeared to be an AK-47-style pistol and a replica AR-15-style Orbeez rifle inside his car.

From there, the juvenile was arrested on an unlawful carrying weapons in a weapon-free school zone charge, which is a state felony.

Marble Falls Middle School and Marble Falls Elementary School, about 45 miles northwest of Austin, operated under safety precautions for about an hour Wednesday afternoon following a report of possible gunfire. The report was later determined to be “unfounded,” according to a Marble Falls Police Department news release.

According to NewsNation’s Houston affiliate, Clear Brook High School was also placed on lockdown after officers arrested a student they say brought an unloaded gun to campus that morning.

The campus, located in the Houston suburb of Friendswood, was placed on lockdown as a precaution. The lockdown was lifted after about 30 minutes.

Police in Donna, Texas, about 280 miles south of Uvalde, arrested two adults and two teens for alleged school threats. Initial reports suggested a search of a student’s home led to the discovery of an AK-47 and a hitlist naming specific students. The local sheriff has since dismissed the alleged hitlist as just a rumor, but confirmed an act of violence was likely prevented.

In Nashville, Tennessee, this week, another potentially terrifying situation was thwarted by a trio of brave women.

Three teachers say they noticed a man who looked out of place lingering by the playground fence.

“As soon as the door was opened to let the kids in, he hopped the fence and started racing to come to the door,” one of the teachers said. “Then I remember just grabbing him and trying to hold on super tight.”

The team effort kept the man from getting inside the school.

Meanwhile, in Sacramento, California, students at a school noticed a loaded handgun in the desk of their second-grade classmate. The students immediately alerted staff.

While many questions remain, an investigation is now underway to determine how that student accessed the weapon in the first place and how the student managed to bring it into the building undetected.

School lockdowns are not unusual. In the 2017-2018 school year, more than 4.1 million students endured at least one lockdown, according to a report by the Washington Post.

Incidents like these and the tragedy in Uvalde, Texas, have prompted some schools and parents to invest in protective gear. An 800% increase in sales of bulletproof backpacks has been reported by one manufacturer in the wake of the Uvalde shootings.