BLACKSBURG, Va. -- The building where a gunman killed 30 people and himself on the Virginia Tech campus will be reopened for offices and laboratories, but it will never again be used for classrooms, the university announced Tuesday.

Norris Hall will open June 18 for the engineering science and mechanics and civil and environmental engineering departments. They had been the primary occupants of the building April 16 when Seung-Hui Cho killed 32 students and faculty members on the Blacksburg campus. Two victims were shot in a dormitory a few hours before the rest were attacked inside Norris Hall.

The second-floor classrooms in the three-story stone building where the victims were gunned down will remain closed.

"That wing is going to be shut down completely," university spokesman Larry Hincker said.

Following the shootings, dozens of faculty, students, alumni and others contacted the school with suggestions for use of the building, ranging from using it as classroom space to making it a memorial to knocking it down.

"After considering all points of view that were offered, I determined the best course of action to enable the College of Engineering to continue its healing was to move forward with phased reuse of the building," university president Charles Steger said in a news release.

"Erasing the building would not erase what happened," said Virginia Tech professor Bryan Cloyd, who used to work in Norris and whose daughter, Austin, was killed there. "I think it would be very difficult for students to have their undivided attention on learning in that building, and so converting it from classroom space is necessary. But I'm happy to hear that the university will have some other productive use for it."

On Tuesday morning, Cloyd visited the second-floor classroom where his daughter died. Since the shooting, he said, it has been repainted, the ceiling has been replaced and there are new floors.

The College of Engineering was hit hardest in the attack, with 11 students and three professors killed.

Norris contains sophisticated laboratories that cannot be moved and are essential to the engineering programs, officials said.

"We have literally dozens of graduate students whose work is frozen in time and unable to move on to jobs or complete their research," engineering dean Dick Benson said in the news release.

Accommodations will be made for people who have a difficult time re-entering the building, Benson said.

"Personally, I don't think I would want to go into Norris at this time," said Susan Bowers, who last month got her master's degree in civil engineering.

Officials said they will post security guards in the building and limit access to employees, students and engineering visitors to cut down on sightseers.

A plan is being developed to convert the building's classrooms to other uses. The university plans to begin a study this summer on the best long-term use of the building.

The building, of local gray limestone, is one of more than 100 buildings on Virginia Tech's 2,600-acre campus. It was named for Earl B. Norris, who served as engineering dean for 24 years.

More than 24,000 signatures have been added to an online petition to rename the building after Liviu Librescu, an engineering and math professor and Holocaust survivor who was shot after he barricaded a classroom door against Cho so students could escape.