Before revision: McGraw-Hill Companies, Inc. ISBN 978-0-07-162395-7.page 347 The 1994 Northridge earthquake revealed a common flaw in the construction , and building codes were revised to strengthen them.
After revision: McGraw-Hill Companies, Inc. ISBN 978-0-07-162395-7.page 347 The 1994 Northridge earthquake revealed a common flaw in steel-frame construction — poorly welded moment connections — and building codes were revised to strengthen them.