Here's what you should know about the Hollywood Fault

HOLLYWOOD (KABC) -- The Hollywood Fault spans about nine miles long from Atwater Village to West Hollywood.

In our lifetime, there's no record of a significant earthquake caused by the Hollywood Fault but seismologists know it's still active.

Seismologists predict that Hollywood Fault will only be disastrous if it erupts in conjunction with the Raymond Fault or the Santa Monica Fault.

"In a sense, the most important part of the Hollywood fault is that there are many vulnerable buildings that would be shaken very violently. You could anticipate many of them would collapse," said Dr. Thomas Heaton, a Professor of Engineering Seismology at Caltech.

"Unfortunately, many of the people that are in the most vulnerable buildings have no clue that they're in the kind of building that collapses in an earthquake," he said.

The Hollywood Fault runs underneath many historic-cultural landmarks in Hollywood like the Magic Castle and the Nirvana Apartments.

The Nirvana Apartments were built in 1925 and once coined the most exclusive apartment building in Hollywood.

In 2015, the city unanimously passed a mandatory ordinance to retrofit any building built before 1978.

Which means taking measures to structurally secure a building so it doesn't collapse in an earthquake.

"If you live in a 1950's or early 70's concrete structure, find a structural engineer to assess the building you're in. If you can get out- I would. If you can't get out, live for today," said Heaton.

Seismologists predict that the biggest earthquake the Hollywood Fault could produce is a 7.0.

The Ridgecrest earthquake was a 7.1.