Can i sue a restaraunt for severe food reaction

My son who is 16 years of age, had a severe allergic reaction to some loaded fries he bought at a restaurant. He took a bite out of it and caused severe reaction. He is anaphylactic, he is allergic to all nuts and shellfish and anything contained. it caused him to swell in his body, swell his tounge, throat closes, swelling of his lips, and eyes, his whole entire body, hives everywhere. He called 911, and was rushed to the pediatric hospital He spent 2 days in the hospital, constantly giving him epiphene, steriods, and benedryl and 5 or 6 IVs. The doctors say they must have cooked the fries in peanut oil, that he is unaware off. My son is a vegetarian, does not eat meat. He ate at a restaurant called Veggie Street, this is the first time eating there, although he did not eat his food at the restaurant but ate it on the sidewalk at the 99 cents store. My son laying on the side walk, people walking by with no one helping him, i got to him on time, as the paramedics did.