NEW YORK » A pedestrian killed by a collapsing crane was eulogized Sunday as a man of kindness and generosity as the final remnants of the crumpled steel were removed from the Manhattan street where they fell.

David Wichs, 38, has been described by relatives as a mathematical whiz who graduated from Harvard University and worked at a computerized-trading firm.

His good deeds also made him “an angel,” said Haskel Lookstein, rabbi emeritus of the Congregation Kehilath Jeshurun, where the funeral was held.

“We honor a very unique man whose life was a life of giving: giving from his possessions to causes he believed in passionately,” Lookstein said.

The recipients included the Yeshiva of Flatbush, which had welcomed Wichs as a 14-year-old from Prague who barely spoke English and knew no Hebrew. “He never forgot it, and he gave back generously,” the rabbi said.

“He gave an unusually large part of his income, but he gave of his person to everybody sitting here,” Lookstein said. “He was a supreme mensch in every respect.”

Wichs’ widow, Rebecca Guttman, called her pain “unbearable.”

“I want you to know that I will do my best to live for us both,” Guttman told her fellow mourners.

Wichs’ remains were taken for burial at Passaic Junction Cemetery in Saddle Brook, New Jersey.

Three other people were struck by debris and injured in the accident Friday.

“Given what happened here, it’s extraordinary that there was not more damage, and it’s extraordinary that we did not lose more people,” Mayor Bill de Blasio said at a press conference Sunday in which he announced a four-point plan to increase safety when large construction cranes are operating.

The mayor said there will be new restrictions on crawler cranes during wind conditions. Fines for failure to safeguard equipment will be doubled. He said there will be increased enforcement of pedestrian safety alongside crane sites. And neighboring buildings will get more notifications about crane activities.

City officials say it could take weeks to determine why the crane collapsed while it was being lowered during strong winds.

Work crews sliced the 565-foot-long mangled crane into dozens of pieces, then used other cranes to load the pieces onto flatbed trucks. Other workers have been concentrating on crushed water pipes and street repairs.