A gun that a first-grader brought to a St. Paul elementary school fired one round in a class full of students Thursday morning, police and the School District said. No one was injured.

Some parents first learned of the incident at Crossroads Elementary when Council Member Amy Brendmoen wrote about it on the Como Neighbors Fun Stuff page.

Police spokesman Sgt. Mike Ernster said his department was alerted at 8:40 a.m. that a 7-year-old student brought a handgun to the school, part of which is Montessori-based.

A statement issued later by police said the gun went off in a classroom full of students. “Thankfully, no one was hurt,” it said.

The statement added that the student who brought the gun to school and his family are fully cooperating as police sort out who owns the gun, how the child got a hold of it and how it could have been prevented.

“Today we got lucky,” the statement read, “but this incident should still serve as a powerful reminder to anyone who owns a gun to keep it safe, secure and out of the hands of children.”

St. Paul School District spokeswoman Toya Stewart Downey said staff confiscated the weapon right away.

Downey added that no threats were directed at staff and students in connection with the gun being in the building. The principal e-mailed a letter to Crossroads families.

“Understandably, students were upset,” Celeste Carty wrote. “Our district crisis team and the police reassured the students that they were safe, that everything was OK and answered questions.”

Downey said that any consequences for the child will follow standard discipline procedures.

It was not immediately clear how the gun fired or if anyone was holding it at the time.

Crossroads is located on Front Avenue, just east of Dale Street N. It operates year-round on a schedule of 45 days on and 15 days off. The school is currently in “intersession,” focusing on math, reading and writing instruction.

Rachel Kane, whose kindergartner and second-grader were in the school at the time of the shooting, said “there will definitely be a conversation about what to do in a situation like this.”

She understands that what she calls “a parent’s worst nightmare” is “something that could happen anywhere.”

Kane said that while she considers Crossroads to be a great school, she is frustrated with how long it took for school officials to release information.

“I got a text from a neighbor who saw something on Facebook,” she said. “After the text, I called the school and “twice I got busy signals, and then it rang and rang and rang” until getting through.

Besides the e-mailed letter, Downey said the school put out a robocall informing all school families of the situation. The principal also called or talked to families of students who witnessed the gun going off.