Students returned Monday to McKinney North High School after an on-campus suicide by a student sent them home early on Friday.
McKinney ISD said extra grief counselors, security and administrators were available to students on their first day back on campus.
"Students, parents and staff have done exceptionally well today supporting each other," the district told NBC 5. "The overall mood at the school is solemn, but respectful and encouraging."
Just before 11 a.m. Monday, the McKinney Police Department posted on Facebook that it was investigating "threatening social media posts." As of Monday morning, the school resource officer at McKinney North had received more than 700 tips in regards to the threats, according to the post.
McKinney police reiterated that extra officers were stationed on campuses across the district this week because it is the final week of the school year.
"We have found nothing to indicate that the student who took his own life at McKinney North High School on Friday had planned to do harm to anyone other than himself," McKinney police said in a statement.
The police department added the student used his father's five-shot revolver and shot himself in an empty classrom.
Thursday is the last day of school in McKinney ISD.
