(CNN) -- A "major tragedy was averted" Saturday as officials announced no one had died in a New Jersey parking garage collapse.

Rescuers had scrambled all night long to find people they suspected were trapped in cars crushed in the rubble of the three-story structure that came crashing down almost a day earlier in Hackensack.

The fears were unfounded, said Hackensack Fire Department Lt. Stephen Lindner.

He said at a morning news conference that "a major tragedy was averted by no one getting crushed under tons of concrete and debris."

Officials said one reason why no one died is because the garage fell after the morning rush hour and because many people were possibly on summer holiday.

The reason for the collapse has not yet been determined, said Joseph Mellone, a Hackensack construction official. An investigation will be conducted.

Lindner said search operations were still ongoing but rescue teams were probing in a much safer way as to not cause a further collapse of the garage.

The garage collapsed shortly before 11 a.m. Friday. Lindner said three stories of the underground parking structure "pancaked," one on top of the next.

State, county, and city workers were working cautiously to avoid secondary collapses. They are digging by hand, at times allowing heavy equipment to remove larger pieces of debris.

Engineers were assessing the structural integrity of the apartments attached to the parking structure. Those living in the apartment building adjacent to the garage were not allowed to stay there Friday night, Lindner said.

Chris Baldo, who lives on the first floor of the building, said the collapse felt like an earthquake. He said he could see the entire collapse from his balcony, adding that his first-floor apartment "looked like it was the fourth floor" by the time the dust settled.

CNN's Rick Martin contributed to this report.