Students on their way to night class might have been confused when the Hennepin County tornado sirens sounded. Go to class or turn back and seek shelter?

According to University spokesman Dan Wolter, there is no hard-and-fast answer to that question.

The National Weather Service issued a severe thunderstorm warning and tornado watch, and the sirens sounded at 5:42 p.m.

Students are advised to take shelter in interior hallways, lower levels and rooms without windows, Wolter said.

The University utilizes a tone alert system to alert around 500 locations around campus in emergency situations, he said.

Vice Provost for Student Affairs Jerry Rinehart said his office heard the tone alerts last night.

“We expect all of our students and faculty to heed the warnings and seek shelter,” he said.

Xcel Energy estimated 18,000 customers in the west metro area were out of power at around 7:30 p.m.

Tom Hoen, spokesman for Xcel Energy, said they didn’t have any areas pinpointed, but that it was likely customers in the University area were without power.

As to whether students should have gone to class last night, professors had varying opinions.

Sociology professor Joel Samaha said he would have expected his students to show up for class, if he’d had a course during the time of the storms.

“I remember when the University of Minnesota never closed,” he said.

Graphic design adjunct professor Greg Pickman said he would cancel class if it were safe for students to leave the classroom.

“My first consideration would be safety, of course,” he said.

As for students on their way to class, “I would expect them to use their best judgment and follow up with an e-mail,” he said, “then it would be an excused absence.”