A five-alarm fire that raged for more than an hour and a half early Sunday caused "substantial" damage to the 400-student Global Leadership Academy in West Philadelphia, Deputy Fire Chief Michael Wahl reported.

The cause of the fire, which started in the basement of the three-story building at 5151 Warren St., near 52d Street and Lancaster Avenue, is under investigation, Wahl said.

Naomi Johnson Booker, chief executive officer of the public charter school, said Sunday that classes might not resume for the rest of the week.

"Everything was lost in the fire," Booker said. "There is not a pencil, not a book, not a crayon. And my teachers don't have any instructional material, lesson plans.

"They need to regroup for the next couple of days and figure out where we are, and then we have to find a place."

A new academy is being built at 46th Street and Girard Avenue, Booker said, but it will not be ready until September.

On Sunday, a school district spokesman said Superintendent Arlene Ackerman offered the charter school a home at the former W.S. Peirce School at 2400 Christian St. in South Philadelphia.

"The facility can be ready so that classes can resume as early as [Monday, Jan. 10]," the spokesman said.

Booker said a visit Sunday to Peirce showed her that it is "in relatively good condition," but there were two problems: "It's in South Philadelphia, and trying to make it as convenient for my parents, my children, as possible."

Global Leadership is a public school chartered by the district and operating with public funds, offering classes from kindergarten through eighth grade to children throughout the city.

The building is tied to the troubled past of the former Raising Horizons Quest Charter School, which moved there in 2006 from 49th and Master Streets in North Philadelphia.

In October 2008, Martha Russell, former chief executive of Raising Horizons, which she founded in 2000, and her sister, Viola J. Bush, the former finance officer, pleaded guilty in federal court to misusing more than $14,000 in taxpayer money for personal expenses.

In June 2009, U.S. District Judge Petrese B. Tucker sentenced Russell and Bush to five years' probation, ordered restitution totaling $24,282 and community service of 250 hours, and placed them on house arrest for six months.

In 2006, the school district had forced the resignations of all but one of the school's board members, as well as Russell and Bush, and assigned a new administrative team to the school.

Booker, the current chief of the revamped Global Academy, said Sunday that she took over Raising Horizons in 2006, moved it to its current site - the former home of Richard Allen Prep - and changed its name and culture.

Booker is leading a movement to improve the image of the city's charter schools.

As president of Philadelphia Charters for Excellence, Booker said in an August 2010 Inquirer story, "I think it is time that our story is told, and that story shows the positive things we're doing."

No one was in the building when firefighters arrived at 5:55 a.m., Wahl said, but two firefighters were slightly injured when they fell on ice. The fire was declared under control at 7:45 a.m.

Mayor Nutter and Fire Commissioner Lloyd Ayers were at the scene, Wahl said.