The cause of Monday morning’s fire at Zeta Beta Tau has been officially classified as “undetermined,” according to Batallion Chief William Dell of the Philadelphia Fire Department.

Dell said the “undetermined” classification is used when fire inspectors cannot identify a probable cause for a fire.

Classifications for fire inspections are conducted based on a standard code established by the National Fire Protection Association.

Before the official determination was made, Division of Public Safety officials said the fire appeared to have started in a first-floor electrical closet at the house, located near 39th and Spruce streets.

Dell said the closet was full of various items such as liquor, costumes and paint products.

The fire was called into the Philadelphia Fire Department at about 10:30 a.m. and was under control by about 11 a.m., according to the Philadelphia Fire Commissioner’s Office.

ZBT brothers are staying in a hotel and in college houses until they can move back in. Office of Fraternity and Sorority Affairs Director Scott Reikofski said Monday he anticipates brothers will be able to move back into the house Thursday, though OFSA “made arrangements for the weekend.”