A Mehlville High School student died this morning after collapsing in class during first period, district officials confirmed this evening.

The student, a sophomore girl, had a congenital heart problem, they said.

She was treated in class by the school nurse and resource officer and taken to an area hospital, but couldn’t be revived.

The south St. Louis County school’s 2,000 students were told by the end of the day, officials said. Counselors were available to students this morning, and will be again tomorrow.

The school did not release the girl’s name.