A school district in Santa Fe, Texas has initiated a lockdown and triggered a “major law enforcement response” after reports of a shooter on a high-school campus. It’s not clear whether this is still an ongoing threat or if the lockdown is cautionary.

BREAKING: Santa Fe, Texas, school district: "This morning an incident occurred at the high school involving an active shooter. The district has initiated a lockdown."

— NBC News (@NBCNews) May 18, 2018

Remember that first details in breaking news stories are not terribly reliable and that it takes a while to get the story correct. This doesn’t sound good, however:

The Harris County Sheriff’s Office confirmed they are also sending deputies to the scene.

Life Flight was also called to the school.

According to students interviewed by KHOU, police got into a gunfight with the suspect. There are unconfirmed reports of injuries:

Some students say they were evacuated down the street to a nearby business as police surrounded the school. There are unconfirmed reports police officers exchanged gunfire with the suspect and there are injuries at the scene.

CNN reports that one girl was shot in the leg, and that the weapon appeared to be a shotgun. NBC reports that ATF is now responding to the scene as well.

We’ll keep an eye on this and update as developments warrant.

Update: I’m following ABC’s Periscope feed, and the parent they’re interviewing says this school had a false alarm two months ago. The police seem to be milling around now, though, which seems to indicate that the threat may already be over. There are a number of ambulances on hand, and there appear to be multiple injuries.

Update: ABC now reporting that their helicopter has seen one body under a sheet, but nothing’s been confirmed.

Update: One LifeFlight helicopter has already transported one person, and there are now three on the ground for others.

Update: The local NBC affiliate says one person is in custody, according to the Galveston police.

Update: The assistant principal confirmed on camera that the police have the shooter in custody, but won’t comment further on any details of the shooting.

Update: Still no word on injuries, but one student tells ABC that his friend spotted the shooter and set off the fire alarm, which may have limited opportunities for targets.

Update: Officially “active but contained,” and confirmation of injuries but not deaths as of yet:

LATEST: "The situation is active, but has been contained," school district says. "There have been confirmed injuries." https://t.co/xC44o8Iu9c pic.twitter.com/zHJYw777lq

— ABC News (@ABC) May 18, 2018

“Active but contained” probably means that investigators have not finished their work, and perhaps also that police have not yet confirmed that all areas are clear of any threats.

Update: Information has been slow to emerge from the shooting, but this is tough news to hear at any time:

BREAKING: According to preliminary information, there have been multiple fatalities at the shooting at Santa Fe High School in Santa Fe, Texas, two law enforcement sources tell CNN

Follow for live updates: https://t.co/iq1ESnf1DE

— CNN (@CNN) May 18, 2018

KHOU is hearing that it may be as many as eight dead:

#KHOU 11 "Three sources telling me that at least 8 students are dead in today's Santa Fe ISD school shooting. More injured." – @JRogalskiKHOU

— KHOU 11 News Houston (@KHOU) May 18, 2018

One has to wonder whether the shotgun was the only weapon used in this instance.

Update: CBS gives a more grim but detailed look at the casualties:

UPDATE: At least 10 are dead in the Santa Fe, Texas, school shooting, law enforcement sources tell CBS News; 2 other students, 1 school resource officer and 1 law enforcement officer have been injured https://t.co/oqRZUFvJK4 pic.twitter.com/lApv68xJLO

— CBS News (@CBSNews) May 18, 2018

The school resource officer would likely have been the first to engage the suspect. Other reports suggest that the perp had both a shotgun and a pistol, which would have allowed him more flexibility in an engagement. And KHOU’s Melissa Correa reports that the perp may have more surprises in store for law enforcement:

#BREAKING::: second scene along Hwy 6, about two miles from the school. Authorities say they’re investigating the possibility of explosive devices inside a mobile home. pic.twitter.com/P7ktSzLxHq

— Melissa Correa (@KHOUmelissa) May 18, 2018

Also, they have the shooter under arrest, but also one other male is being detained as “a person of interest.”

"One male is in custody. And then a second one, again, was a person of interest. Both are believed to be students here at the school," Harris County, Texas, sheriff Ed Gonzalez says https://t.co/oqRZUFvJK4 pic.twitter.com/FPc8I9Zr6A

— CBS News (@CBSNews) May 18, 2018

Update: NBC’s Pete Williams is also hearing about explosive devices:

NBC's Pete Williams: Several law enforcement officials have told us that they've found explosive devices. It's unclear how many or where.

— Jesse Rodriguez (@JesseRodriguez) May 18, 2018

Update: Reuters reports that police have found potential explosive devices at multiple locations:

JUST IN: Possible explosive devices found at Santa Fe High School and off campus after shootings: school district on Twitter pic.twitter.com/KKGWQlqbOc

— Reuters (@Reuters) May 18, 2018

If this is true, someone had to know of the threat before today.

Update: Local law enforcement has confirmed the existence of multiple explosive devices inside and outside the school:

https://twitter.com/TheWorldsFrates/status/997515061387321345

Give the officials there lots of credit for keeping the media abreast of all these developments. The breadth of this attack and its level of preparation raise all sorts of questions. How did this threat get missed? This is clearly not an impulse attack.

Update: One of the dead is a teacher, CNN reports; the other nine are students. Meanwhile, the suspect has been identified as Dimitrios Pagourtzis.

NEW: Santa Fe shooting suspect has been identified as 17-year-old Dimitrios Pagourtzis, law enforcement sources tell CBS News https://t.co/oqRZUFvJK4 pic.twitter.com/LNUDlIk1sA

— CBS News (@CBSNews) May 18, 2018

The search-warrant discussion here is pointless. Police will stay on site until the warrant is issued no matter whether Pagourtzis is a juvenile or not. Nothing will disappear while that happens.

Interestingly, there seems to be no social-media footprint for Pagourtzis.

Update: Looks like “person of interest” is morphing into “accomplice”:

UPDATE: A second person in custody is 18 years old and is believed to be a possible accomplice to the suspect in the Texas shooting, but not the shooter, according to a law enforcement official, reports @evanperez

— Ana Cabrera (@AnaCabrera) May 18, 2018