Medical event cited in fiery Somerville crash that injured 3

SOMERVILLE — A fiery crash that seriously injured three people, including a 16-year-old pedestrian, was triggered when the driver of a Hyundai Sonata suffered a medical problem and then collided with a Honda Civic that burst into flames, State Police said.

The crash took place at about 8 a.m. at the intersections of the McGrath Highway and Medford Street in Somerville and ultimately involved a total of five vehicles and at least six people, three of whom were injured, State Police said.

The 16-year-old male was initially believed to have been ejected from one of the vehicles, but then his father arrived and identified clothing lying on the sidewalk as belonging to his son, and officials realized he was on foot when struck.

“He was about to break down. He was panicking,’’ said Esha Burnett, a Somerville resident who was walking by the intersection when the man arrived. “I saw a few tears come from his eyes, and I started to have tears myself.’’

Police drove the teen’s father to Massachusetts General Hospital, where his son was taken, officials said. State Police said the teenager is believed to have suffered injuries that were serious but not life-threatening.

Somerville Deputy Fire Chief Bill Hallinan said all three of the injured — the teen and the drivers of the Sonata and the Civic — were taken to Mass. General. The two drivers both suffered serious injuries.

A pedestrian, 16, was one of three people injured in this fiery five-car crash on McGrath Highway and Medford Street in Somerville on Friday morning.Aram Boghosian for The Boston Globe/Globe Freelance

In a statement, State Police summarized how the crash unfolded:

The Sonata driver, a 56-year-old woman, suffered the medical problem and collided with a 2005 Honda Civic operated by a 26-year-old Medford woman. The chain reaction continued until it also involved a 2012 Ford Focus hatchback operated by a 51-year-old Somerville woman, a 2002 Honda Accord operated by a 38-year-old Somerville man, and a 2001 Toyota Sequoia SUV operated by a 28-year-old Somerville man.

After being struck, the Civic burst into flames and was so heavily damaged that the make of the vehicle could be determined only by the Honda symbol on the hubcaps.

Hallinan said people in the vehicles and from the neighborhood rushed into the intersection to help drivers out of the cars after the crash.

Somerville Schools Superintendent Tony Pierantozzi said that the teen is a student at Full Circle High School.

“Our thoughts are with the student and his family at this time,” Pierantozzi said in a statement. “We are hoping for the best possible outcome for all involved, and are prepared to offer whatever support we can to the student, his family, and to the Full Circle community. “

State Police said that because the chain-reaction crash stemmed from a medical issue with the driver of the Sonata they will not be citing her for any traffic violations.

The names of the people involved will not be released, State Police said.

State Police closed the entire highway for about a half-hour.