The Wall Street worker crushed by last week’s massive crane collapse was eulogized Sunday as a man of kindness and generosity, even as officials announced measures intended to prevent similar accidents in the future.

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

At Sunday’s funeral, the 38-year-old’s widow, Rebecca Guttman, called her pain “unbearable.”

“I want you to know that I will do my best to live for us both,” she told her fellow mourners at Congregation Kehilath Jeshurun on the Upper East Side.

Wichs was “a brilliant mathematician and a man who, despite his brilliance, was known for his humility and his grace,” Mayor de Blasio said a few hours after the funeral, as he announced new rules meant to increase crane safety around the city.

The new measures, which go into effect Monday, require that tall crawler cranes go into safety mode whenever the forecast predicts winds of 20 mph or more. Crawlers like the crane involved in the collapse are mounted on an undercarriage with tank-like caterpillar tracks to provide mobility.

The city will also require increased efforts to keep pedestrians off the street in areas where large cranes are being operated, and residents will be informed before cranes in their area are moved, de Blasio said.

The announcement came hours after work crews finished slicing the 565-foot-long mangled crane into dozens of pieces, which were loaded onto flatbed trucks and driven away. Other workers continue working to repair crushed water pipes and damaged street surfaces.

City officials say it could take weeks or even months to determine why the crane collapsed while it was being lowered during strong winds. Three other people were struck by debris and injured in the accident Friday.

At Wichs’ funeral, Rabbi Haskel Lookstein said that Wichs’ good deeds made him “an angel.”

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