Firefighters were called to Jake's Diner on Alden Road just before 1 p.m. on Monday. When they arrived, they found heavy flames on the back of the building.
Residents in Lawrence, Andover, and North Andover have joined a class action lawsuit against the company that supplies natural gas to those communities.
A series of gas explosions has killed a teenager, injured at least 10 other people and ignited fires in at least 39 homes in three communities north of Boston.