Harvard Medical School building reopens as police investigate explosion

This photo shows a person of interest in an explosion at the Harvard Medical School in Boston, on Saturday, Nov. 1, 2025. (Harvard University Police Department via AP)

BOSTON — A Harvard Medical School building has reopened while a “very active” investigation continues into a weekend explosion that authorities said was intentionally set off.

An officer who responded to a fire alarm early Saturday morning encountered two people running from the Goldenson Building, according to university police. The explosion occurred on the fourth floor of the building, which houses labs and offices associated with the medical school’s Department of Neurobiology.

The Boston Fire Department determined that the explosion was intentional and officers did not find additional devices in a sweep of the building, police said. No one was injured.

“The small section of the fourth-floor hallway where the explosion took place has been cleared and is fully operational. There was no structural damage to the building, and all labs and equipment remain intact,” medical school officials said in a statement.

An FBI spokesperson declined to comment Monday other than describing the investigation as “very active.” Police released grainy photos of two people wearing face coverings and what looked like sweatshirts.

In recent months, U.S. President Donald Trump has targeted Harvard with a series of investigations and billions of dollars in funding cuts as it presses for changes to its policies and governance.

The Associated Press