A fire heavily damaged five businesses in a strip mall in the South Whittier area early Tuesday, including a landmark restaurant, authorities said.

Firefighters sent to the 13500 block of Telegraph Road about 2:25 a.m. doused the flames in about 40 minutes, according to the Los Angeles County Fire Department.

No injuries were reported. The cause of the fire, which resulted in "major damage," was under investigation, the county fire department reported.

Among the businesses damaged was Pizzamania, said Los Angeles County Supervisor Janice Hahn.

"Early this morning, a fire tore through five businesses in a strip mall on Telegraph Road in South Whittier, including Pizzamania -- a beloved institution in this community for 50 years," Hahn said in a statement.

"L.A. County Firefighters responded quickly, but the restaurant is almost completely destroyed," Hahn said.

"I know that both the business owners and the employees alike are facing a very difficult time in the wake of this fire and I will be directing our L.A. County Department of Economic Opportunity and Department of Consumer and Business Affairs to connect these workers and businesses so that we can offer any help and support we can."