Police said four men carrying baseball bats stormed the store just before 9 p.m. Monday. The suspects smashed display cases filled with jewelry.
A mall security guard was able to catch one of the robbers, but the other three got away with an unknown amount of jewelry.
A woman who witnessed the robbery suffered a heart attack, according to officials. She was transported to a hospital and is reportedly doing OK.
Authorities said department store robberies are common during the holiday shopping season.
"It is time of year where there is increased shopping, and we do have an increase in robberies within commercial businesses. We also have an increase in burglaries from motor vehicles occurring at shopping centers," said Lt. Al Lopez of the Los Angeles Police Department.
Officials warned shoppers to be careful and monitor their surroundings.
Anyone with information about the robbery was asked to contact Los Angeles police at (877) LAPD-24-7.