WEST LAFAYETTE, Ind. — A routine day of classes was pierced by the sounds of gunfire, fire alarms and screams when a Purdue University student entered a basement classroom and shot and killed a fellow senior engineering student from Wisconsin, whom a former teacher described as having a “brilliant mind.”

Police haven't determined why Cody Cousins, 23, shot Andrew Boldt, a 21-year-old teaching assistant from West Bend, Wis., inside the school's Electrical Engineering Building about noon Tuesday.

Purdue Police Chief John Cox said witnesses believed the shooting was “an intentional act” but said there was no immediate indication Cousins and Boldt had past troubles.

No one else was injured, and Cousins is being held at the Tippecanoe County Jail on a preliminary charge of murder.

Cousins surrendered to a police officer outside the building after firing four or five shots, Cox said.

Theprompted Purdue President Mitch Daniels to cut short a weeklong university trip to Colombia and cancel classes Tuesday and today.