LYNN – An unfortunate fireworks mishap on Birch Street left two young boys severely burned Saturday, fire and police officials said.Rescuers responded to 82 Birch St. shortly after 5 p.m. Saturday.An 8-year-old boy was the most seriously injured with third-degree burns over 30 percent of his body. A 12-year-old boy had similar burns over 10 percent of his body.Both of the victims are from New York City and were visiting family friends with their parents for the July 4th weekend, authorities said.A third boy, age 10, a Boston resident, suffered blisters and minor burns as a result of the incident.The two seriously injured boys were immediately transported to Mass. General Hospital in Boston. According to Lt. Dave Legere, investigator for the Lynn Fire Department, the 8-year-old boy was since transported to the Shriners burn center because his injuries were so severe.As of Monday afternoon, Legere said investigators have been unable to speak with the boys or their parents about the incident.A six-by-four foot scorch mark was found on the sidewalk when investigators arrived, he said.Legere said the family was visiting people in Lynn, who then brought them to Birch Street for a gathering.Legere described the explosive device as being softball shaped. He couldn’t positively identify the device, but speculated it’s probably an explosive that is usually placed into a pipe so it can shoot upward.However, when not placed into a pipe it shoots outward.Two rocks were found nearby, and investigators are examining the possibility that the boys smashed the rocks against the explosive when it detonated.”I tend to think they were probably banging these things with fireworks,” Legere said.Both Legere and police say the adults were likely in the backyard or another area of the home and the children were playing on the sidewalk when the accident occurred.So far, authorities have only spoken to the residents of the home and were not able to speak with the parents, who have been at the hospital since Saturday.They have no idea where the explosive came from.”Whether they found this in somebody’s yard or not, we don’t know,” Legere said.Legere says it doesn’t appear criminal charges will be filed at this time.”It’s an extremely unfortunate accident,” he said.