A blast believed to have been caused by an explosive device damaged two rooms at Yale Law School on Wednesday but caused no injuries, authorities said.
The explosion, which occurred about 4:40 p.m. Eastern time, toppled a wall shared by a classroom and an adjacent lounge but did little other damage to the law school building, which like the rest of campus was largely deserted, according to New Haven Mayor John DeStefano Jr. and Yale officials.
Though most undergraduates had already left campus for the summer, law students took final exams in the law building earlier in the day, DeStefano said. But no one was in the classroom at the time of the explosion, he added.
“Basically, there’s not anything going on. There’s no programming going on on campus right now. It’s a very quiet time,” DeStefano said Wednesday evening.
The mayor said that city fire officials told him the explosion was caused by “some kind of device,” but he cautioned that that had not been confirmed.
Michael Wolf, an FBI special agent, said Wednesday night that physical evidence was being gathered for analysis -- a process that he said would take a couple of days. At the same time, he added, interviews were being conducted to determine who was in the building between 1 and 5 p.m.
Bomb-sniffing dogs had checked about 80% of the building by Wednesday night, turning up no additional explosives, Wolf said.
The law school building includes housing for 40 students, who have been moved to other quarters, and a day-care center located “away” from the bombed classroom, DeStefano said. Some children were in the center at the time of the blast, the mayor added.
Lisa Bull, spokeswoman for the FBI’s field office in New Haven, said she had no additional information about the nature of the device. “We simply are describing it as an explosion,” Bull said.
No motive had been established, authorites said.
The blast, which startled some students nearby and sent smoke into the air, came a day after U.S. homeland security officials elevated the nation’s terror-alert status to high following bombings in Saudi Arabia and Morocco and intelligence reports suggesting the possibility of attacks against the United States. Earlier Wednesday, President Bush gave the commencement address at the Coast Guard Academy in New London, Conn., 50 miles away.
Bush is a Yale graduate and one of his daughters, Barbara, is a student there.
Students who were in the building when the explosion occurred told reporters they heard a loud noise and felt a sudden shaking sensation that one said was what he imagined an earthquake would feel like.
A law student, Bob Hoo, told Associated Press that he “saw a huge fireball come out to the middle of the hallway.” Hoo said he was on the ground floor of the law school: “It was there and then it was gone.”
But others who were in the building -- a rambling Gothic-style structure covering a city block -- said they were unaware of the explosion in Room 120, which holds about 100 students.
Yale’s commencement is scheduled to take place Monday and will proceed as planned. University officials said extra security is always maintained at graduation ceremonies.
Mulligan reported from New Haven, Ellingwood from Atlanta. Times staff writer Richard B. Schmitt contributed to this report from Washington, D.C.