The fire that scorched the second floor of Ell Hall April 2 has been ruled an arson by the Boston Fire Department Arson Squad, Northeastern Associate Director of Public Safety James Ferrier said.

The fire is still being investigated by the arson squad, Northeastern Police and Northeastern’s property insurance carrier, Ferrier said. Because the investigation is ongoing, Ferrier said he cannot comment on whether there are suspects in the case.

“The investigation is continuing,” he said. “There have been about three dozen people interviewed.”

Samantha Sang, a middler sociology and communications major, was one of those called in for questioning. She said she doesn’t know why she was called in, but suspects it might be because she swiped into her residence hall after 6 a.m. Sunday.

“They asked me what I was doing that day,” she said. “It must have been when I swiped in, because I wasn’t anywhere in the area.”

Ferrier said the fire department determined the cause of the fire was arson based on evidence at the scene, eliminating accidental causes.

“Physical evidence at the scene gave indications immediately once the fire was out and they could look at the site,” he said. “There were early indicators that it was not electrical, not accidental, and that’s how you get toward arson; you rule out the causes that can start a fire by accident.”

This fire is not the first in Ell Hall. On Dec. 19, 1996, a fire destroyed the Bacon Memorial Chapel, which was in the location that is now the Sacred Space. The Sacred Space was then created, and was finished and dedicated in 1998, Ferrier said. The fire occurred right before Christmas break, and caused smoke damage to every floor.

At the time, the Northeastern Voice reported that the Boston Fire Department had ruled that blaze was also arson, but Public Safety records do not confirm that.