Same school:

https://www.chron.com/neighborhood/galveston/news/article/Santa-Fe-High-School-on-lockdown-12717319.php

They couldn't verify the threat. Note date. Post Parkland, but same school.

However, the rumor going that THIS other threat was traced to Galveston isn't holding water so far. Still digging.

https://newsok.com/article/5585240/threats-investigated-at-del-city-middle-school-edmond-santa-fe-high-school.