An entire entryway in Eliot House was left homeless late Saturday night after a prankster sprayed a fire extinguisher, flooding the entryway with powdery chemicals and leaving students searching for a place to sleep for the night.

Cambridge firefighters responded to an alarm in Eliot’s D entryway at around 2 a.m. yesterday, causing residents to gather outside the building. After about 30 minutes outside, tutors informed the residents of D entryway that they would not be allowed back into their rooms—and told a frigid crowd that any student found in the closed entryway would be arrested.

The 34 displaced students were left to spend the night on friends’ futons or on Eliot Junior Common Room couches, tutors said.

The fire alarm was set off when someone sprayed the fire extinguisher at the fire sprinklers, according to Michael C. McGaghie ’01, the Eliot tutor on call at the time.

“The alarm went off because of what the fire department determined to be a prank that required excessive cleanup of an entryway in Eliot House,” he said.

Students were not let back into their rooms “due to tonight’s fire extinguisher discharge and the resultant unsafe conditions,” according to an e-mail sent by McGaghie to students.

Geoffrey L. Werner-Allen ’02, the D-entryway tutor, said that the decision to close the entryway was made to “clear the discharge from the fire extinguisher.”

But several students told The Crimson that their tutors had informed them of another reason for closing the entryway: The fire extinguisher discharge had clogged the sprinklers, temporarily rendering them defective and creating a potential liability.

“The air was full of what we thought was smoke at the time, but it didn’t smell like smoke, and it wasn’t hot,” said Nicole K. Efron ’08. “But it hurt to inhale it.”

Dominique Gracia ’09 said that when the alarm went off, “the entire area was completely white,” and “we couldn’t really breathe.”

Urvesh M. Shelat ’09 said that it took him a moment to realize that it wasn’t smoke.

“Someone had just taken a fire extinguisher and run up and down the stairwell,” he said.

While the students gathered outside, the residents of D entryway were escorted into the dining hall and informed that the area had been closed down.

“It wasn’t a panic,” Efron said. “At that point, we knew that it wasn’t a real fire.”

For one student, not being allowed back into his room was particularly frustrating.

“There was one kid outside in his boxers who was like ‘I just need pants,’” recalled Shelat, who is also a Crimson design editor.

According to Werner-Allen, several Eliot students offered to host displaced D-entryway residents after the fire alarm went off.

“There were about a dozen Eliot students that actually came aside to offer futons and couches and other forms of accommodations,” he said.

The entryway was reopened yesterday morning.

—Staff writer Reed B. Rayman can be reached at rrayman@fas.harvard.edu.