Eastern Senior High School opened its doors a day late and a principal short yesterday, and more than one-fourth of its students were absent as the District's school system failed for a second day to produce a schedule of classes and room assignments.

The roughly 665 students who showed up -- out of an estimated enrollment that has varied from 900 to 1,064 students -- spent the day in homeroom, discussing current events such as the war in Iraq and the presidential campaign and working on math problems.

"If you didn't keep yourself busy, there wasn't anything to do," said Loretta Miller, 17, a senior who is president of the school's well-regarded choir.

Eastern was the only one of the city's public schools that did not open Wednesday, but the situation caused significant embarrassment for the system. Yesterday, top city officials applauded the decision to fire three officials: Eastern's principal, an assistant superintendent and a technology specialist. Interim Superintendent Robert C. Rice dismissed the three Wednesday afternoon with support from Clifford B. Janey, who is to start work Sept. 15 as the city's fifth superintendent in nine years.

Wilma F. Bonner, Eastern's new temporary administrator, said class schedules may not be available until Tuesday, but she issued a public appeal for absent students to attend. "I hope that the community will encourage them to come," she said.

Students will spend another day in homeroom today, but they will receive work in reading, math and science, Bonner said.

At the school system's headquarters near Union Station, scheduling specialists from schools across the city joined a team of technology specialists in the tedious work of assembling Eastern's schedule -- a process that should have been completed last month.

Since Wednesday, the employees have been working round-the-clock on the fifth floor of the system's headquarters at 825 North Capitol St. NE. The stress was so great, officials said, that one computer specialist had an asthma attack Wednesday night and had to be taken to a hospital for treatment.

For about a decade, the school system has used a software product called People Oriented Information Systems for Education to compile school schedules and record student grades.

The scheduling system is complex and only partly automated, according to Charles T. Thompson, the school system's chief technology officer. For high schools, it involves thousands of paper forms submitted by students that are then entered into a computerized system. The system assigns students to classes based on several factors, including maximum class size.

Administrators need to reconfigure schedules repeatedly by hand to reduce the number of scheduling conflicts and then run the system again. The back-and-forth process is supposed to produce a master schedule with at least 95 percent of students not having conflicts. Any remaining scheduling conflicts are resolved manually.

Rice said last night that successful schedules had been produced for only 15 percent of Eastern's students by yesterday morning. When the computer specialists took over the scheduling process late Wednesday, they found it in disarray, Rice said. "The whole piece fell apart. . . . They have had to re-create the master schedule," he said.

The antiquated software system -- made by Campus America of Knoxville, Tenn., which has since become part of Jenzabar Inc. of Cambridge, Mass. -- is scheduled to be replaced. The new system, which allows scheduling to be done at schools, was launched on a trial basis at McKinley Technology High School this summer, Rice said.

Although the current software is unwieldy, the failure at Eastern was ultimately the principal's, Rice said, noting that all other high schools managed to complete their schedules on time. He said Principal Norman S. Smith Jr., who was hired in August 2003, did not fully understand the system or accept help that was offered. Smith has declined to comment.

"We've got to get the message out that there are no excuses there or anyplace else," Rice said last night, adding that he expected the firings to be controversial. "I know it comes with a lot of risk."

City Administrator Robert C. Bobb said Mayor Anthony A. Williams (D) backs the firings. "We believe those were the appropriate actions to take," Bobb said. "It's really time to let everyone know that this is a new day in the District of Columbia and that accountability really matters. We are in full support of the action that the superintendent took."

In a radio call-in show, Police Chief Charles H. Ramsey also supported Rice. "If you accept mediocrity, that's exactly what you're going to end up getting," Ramsey said. "I was pleased to see the principal at Eastern get fired yesterday. There was no excuse for that school not to be open. I mean, that's just trifling. Here's a guy who's the principal of the high school and can't get a schedule together and then throws the kids out on the street."

Bonner, who joined the school system in 1970, is the sixth person to head the school since Ralph H. Neal departed in 1997 -- after more than 12 years in the job -- for a position in the school system's central office.

After so many principals, "you don't trust anyone anymore," said Tina Bradshaw Smith, who has taught health and physical education at Eastern for 18 years. "We're not sure what's going to happen."

Students appeared split on the decision to fire Smith. "I've had four principals now in my four years here," said Erica Mayo, 16, a senior, who lives in the Congress Heights neighborhood of Southeast Washington.

"I thought they were going to keep this one," she said of Smith. "He was a pretty good principal. You saw him all around the school, poking his head into classrooms to enforce order. The first two years I was here, I didn't even know what the principal looked like."

Among new students, there was less sympathy for Smith. "The principal should have been responsible," said Ashlei Frazier, 15, a sophomore who attended Hine Junior High School last year.

Staff writer Monte Reel contributed to this report.