Nina Brown returned to Washington last week primed to start her second semester as a biology major at Howard University. Instead, she learned something about the biology of buildings beset by an arctic blast.

"The first day, it was cold throughout the building," Brown said. "And then the second day, the heat started working in our room. But in different rooms on my floor, some are cold, some are hot."

Amid the frigid start to the new year, Howard found itself facing concerns about the state of its facilities. The cold weather sparked power outages, heating woes and damage to campus buildings. Undergraduate classes were postponed. And the school was still making repairs even as it prepared to start the delayed semester Tuesday.

"I don't really know how it happens," said Brown, 18. "D.C. is a cold city, so I don't know how they weren't prepared. But all the students are safe."

Jade Agudosi, president of the Howard University Student Association, said last week that the organization received worried calls from students: They had heating problems. There was no hot water for showers.

"So, it's pretty much chaos right now . . . from the student perspective in terms of just coming back and then experiencing all the wrath of the winter," she said. "Overall, people are just trying to stay warm, and I think that's the biggest thing."

Howard's president, Wayne A.I. Frederick, weighed in on the mess in a video, calling the damage "very serious" and explaining that the cold caused ruptures in the university's steam pipes. That led to flooding and water damage, he said.

In the video, Frederick called the issues Howard was facing a "priority of my entire administrative team."

Some of Howard's boilers — which deliver heat to residence halls and other campus buildings — also stopped functioning properly, although Howard University Hospital maintained heat throughout the emergency, Frederick said.

He mentioned the three buildings with the most serious damage and said they were "offline" as personnel workers dehumidified and repaired the sites.

"Because of the severe damages, these buildings will likely remain offline for quite some time," he said.

To understand the crisis at Howard, it is necessary to dive into the nitty-gritty of the university's infrastructure.

As the temperature fell, steam distribution was compromised, said Tashni-Ann Dubroy, Howard's chief operating officer. Even though boilers were pumping steam toward buildings, the heat was escaping through ruptures in pipes.

"It worsened because the temperatures never let up," she said.

There was no easy fix, Dubroy said. "It was probably one of the most unfortunate circumstances we could have experienced," she said of the boiler malfunctions. "That failure certainly put us in a significant crisis."

The university does not have an estimate for the cost of repairs.

"But from the looks of it — this is me being an unofficial estimator — it's multimillion-dollar damage that has been done to the campus," Dubroy said.

Howard freshman Jamen Rollins, 19, said he was a bit nervous returning to campus.

He returned to a dorm that had heat and hot water. But he knew of others who had come back to campus earlier and were more affected.

"Howard just needs to do better," Rollins said. "It's pretty much unacceptable, I think. I'm supposed to be in class right now, but they pushed it all back because of the problems we've been having."

Last week, Howard alumni and students' family members got in touch with the school to offer help, said Agudosi, the student association president. And Howard students who had heat and hot water opened their doors to those who needed a warm refuge.

"That is the Howard spirit," Agudosi said. "Even in spite of all the different challenges that we are facing, we are a resilient campus, and we have a resilient student body. . . . No matter what hardships come our way, we're always able to weather the storm, literally and figuratively."

A previous version of this story incorrectly indicated that Howard University's steam pipes froze during recent cold weather. Howard's sprinkler and domestic water pipes froze. Its steam pipes fractured, but did not freeze.