Most of the ceiling in Stoughton North 29 fell to the floor just before noon yesterday, sending dust and large chunks of plaster raining down on the heads of the students in the room and on their possessions.

Three first-years students suffered minor injuries from the collapse.

Students pulled the fire alarm, and police and fire units responded. The Cambridge Fire Department used hooks and pikes to pull down more of the ceiling while the Harvard University Police Department (HUPD) shut down the building.

Timothy L. Lyons '04 was in the room when the ceiling collapsed.

"We didn't really see what happened, there was a lot of dust," Lyons said. "We just got out of there."

Hollis Hall resident Tessa V. Gonzalez '04 said the ceiling collapse was not preceded by any large noise or movement in the building.

"This was just random--it wasn't like an earthquake or anything, just boom," added Tessa V. Gonzalez '04 of Hollis.

Lyons and the other students in the room at the time received only minor scratches and bruises--nothing that required medical attention.

Engineers immediately began work in the building while police officers cordoned off the area.

About 90 minutes after the initial incident, first-year dorm manager Kathleen A. Bray ordered Hollis Hall--built at the same time as Stoughton--evacuated as well. HUPD officers went door-to-door asking residents to leave the building.

Students gathered on the steps of their dorms while state building inspectors and Yard Operations personnel inspected the building.

Residents of the bottom three floors of both dorms were readmitted to their rooms early last evening.

Students on the fourth floor of Stoughton were housed overnight in Loker Commons where the College set up cots, towels and blankets and added special security. Loker was closed to all other students.

Inspectors from the Department of Physical Resources checked the building to determine whether the same dangerous condition existed in other rooms.

"Just one room was impacted with the physical damage," Harvard spokesperson Doug L. Gavel said.

Representatives from Harvard's insurance office will be meeting with students and their families to determine whether any belongings will need to be replaced.

The Freshman Dean's Office did not respond to requests for comment.

Officials cautioned that yesterday's incident is not indicative of any widespread problem in the Yard dorms.

"This was obviously just one incident in one dorm room," Gavel said. "The most important thing is to determine why and how this happened before anyone decides this a matter of a concern."

Stoughton and Hollis were both renovated in 1994, the work including new ceilings, walls and hardwood floors. But the ceilings in Hollis were finished differently than in Stoughton and thus are not as much a cause of concern, Gavel said.

The current Stoughton Hall is the second building of the same name to occupy the space, and is named after the first graduate to fund a building, William Stoughton, Class of 1650. The college razed the first Stoughton because of damage incurred during the Revolutionary War.