LOS ANGELES — Researchers have decided to hand the city of Los Angeles a list of older concrete buildings, some of which may be prone to collapse during a strong earthquake.

An estimated 75 of the 1,500 concrete buildings around Los Angeles County identified by a team led by the University of California, Berkeley, could topple during violent shaking, the Los Angeles Times, reported Saturday.

The announcement Friday, on the 20th anniversary of the Northridge quake, which killed 57 people, will help the city determine which buildings are at risk and take steps to retrofit them.

City officials have known about the potential dangers of concrete buildings for more than 40 years, but have not forced owners to strengthen them. Such buildings may be vulnerable during a quake because they don’t always contain enough steel reinforcing bars.

Researchers were initially reluctant to share their database because of fears of being sued by property owners. But they changed their minds after completing the federally funded project.

“We would like to be helpful to the city, to help them move forward” on this issue, UC Berkeley engineering professor Jack Moehle told the Times.

He said the handoff would occur next week. Buildings on the list were built before 1980 and researchers stressed that not all are considered dangerous.