After learning that a small plane had rammed into the heart of a luxury condominium he designed, architect Frank Williams rushed to 72nd Street to survey the damage.

The flames and black smoke shooting out from the windows on the 30th and 31st floor looked menacing, but the architect was confident that the 50-story Belaire would prove sturdy.

Mr. Williams, who has designed more than 20 buildings in the city, told The New York Sun that the Belaire, perched near the windy edge of the island across from Roosevelt Island, was constructed with reinforced concrete designed to sustain a large kitchen blast. He said he never thought the building was in danger of collapsing, despite the ferocity of the fires that gutted at least two apartments.

The red-brick Belaire was developed by the Zeckendorf family, one of the city’s biggest residential builders, and completed in 1988, part of the neighborhood building boom sparked by Sotheby’s move to York Avenue earlier in the decade. It’s been said that the condominium’s asymmetric façade faintly resembles 30 Rockefeller Plaza.

The first 22 stories are owned by the Hospital for Special Surgery, which is ranked as the best hospital in the northeast for orthopedics and rheumatology, according to U.S. News and World Report magazine. The first 12 floors serve as offices, and the next 10 are housing for hospital staff and guest facilities.

The rest of the building is a luxury condominium, whose residents include suspense novelist Mary Higgins Clark and the founder of Cigar Aficionado magazine, Marvin Shanken. According to brokers, available apartments run from about $500,000 for a studio to more than $1.6 million for a two bedroom.

At the time of the crash, a real estate broker, Donna Olshan, was in the penthouse apartment, which is on sale for $4.8 million, preparing to meet with a client.

“The building shook. It was like being in mini-earthquake. The walls shook for about five seconds,” Ms. Olshan said.

She said she evacuated the building using the stairwell and could smell smoke around the 30th floor. “I just kept flying down,” she said. “I didn’t know what I was heading into, but I knew one thing: I had to keep going.”

Will the accident deter potential buyers skittish about making their home in a building with such an unlucky streak?

“My sense is that it was a freak accident. I don’t think freak accidents affect pricing,” a broker for Prudential Douglas Elliman who has a listing in the building, Jason Haber, said. “Maybe in the beginning people will be a little intimidated.”