WEYMOUTH — A deafening boom rocked the houses near Union Street around 11 Saturday night, when an SUV carrying four teenagers veered off the road, crashing into a utility pole, a parked car, then a nearby tree, according to neighbors and authorities.
Kate McCarthy, 15, of Weymouth, was ejected from the vehicle during the collision and later died at South Shore Hospital, according to a spokesman for the Norfolk County District Attorney’s office.
The three other teens — a girl and two boys — were also taken to the hospital, police said. As of Sunday evening, their conditions and identities were not known.
All of the students were identified by school officials as sophomores at Archbishop Williams High School in Braintree.
“The teachers are grieving. The students are grieving, all of us,’’ said an emotional Michael R. Volonnino, principal of Archbishop Williams, in his office at the school Sunday afternoon. “It’s a tragedy.’’
Adalberto Rodriguez, a Boston firefighter and EMT who was recognized for bravery during the 2013 Boston Marathon bombings, was in bed when he heard the ear-splitting noises outside. Pieces of the light pole flew into his yard, he said.
“They hit the light post in front of my home,’’ he said in telephone interview. “Tore it to pieces. It was broken up from the bottom. Went through our yard, hit my car in the driveway.’’
Rodriguez rushed outside, he said, and administered chest compressions on McCarthy and the other girl, who also had been thrown from the SUV and landed on a neighbor’s porch.
The boys were less seriously injured, Rodriguez said.
Rodriguez’s actions mirrored his state-recognized bravery in 2013, when he and other EMTs rushed toward the second explosion during the Boston Marathon bombings and treated several victims, including 8-year-old Martin Richard. In 2014, Rodriguez was awarded the fire department’s Edward H. Hommel, M.D. Medal of Honor for his actions.
“I’ve been on the job for 20 years, so I’ve seen my share,’’ Rodriguez said.
Lynne McGrath, Rodriguez’s neighbor, said she was up watching the news on television when she heard an engine revving and a vehicle speeding past her home.
“We’ve always had a problem with people tearing down this street,’’ said McGrath, who has lived on Union Street since 1990. “But I knew this one was bad, because I heard it coming. [They] were zooming down the street, and I thought, ‘That car is going to crash.’ ’’
Authorities have not released a cause for the crash and have not indicated whether speed was a factor. No criminal charges were filed as of Sunday night, according to authorities.
Other neighbors, including Rodriguez, Al Hoban, and Ocean Waller, said they did not hear the SUV speeding. When they heard the crash, they said they thought it was gunshots or a lightning strike.
Waller, 51, said she called 911 when she looked outside and saw the damaged SUV. She feared the fallen electric pole could ignite a fire, she said.
Hoban, 75, did not learn the crash was fatal until the next day, after a friend called him.
“It’s a shame. A tragedy,’’ Hoban said. “The street is just wide enough where people think they can speed. But to knock that light pole over, they had to be going pretty fast.’’
At McCarthy’s family home in South Weymouth, where dozens of relatives and friends gathered in the afternoon, men could be seen hugging outside and several young teenagers arrived carrying flowers and cards. They declined to comment on the crash.
Earlier in the day, at the crash site near 583 Union St., friends of McCarthy and her family laid flowers near the light pole, which had been quickly repaired.
One woman, who asked not to be identified, said McCarthy was a “great, sweet girl.’’
Two high school students, who did not attend Archbishop Williams High School but knew McCarthy, called the 15-year-old a “sweetheart.’’
The students asked to not be named because McCarthy’s family had not commented.
“You never heard anyone say anything bad about her,’’ said one 17-year-old, adding that it “could have been any one of us.’’
A 16-year-old, who said he brought flowers out of respect for the family, said local teenagers were “completely shocked’’ to hear about the crash.
In a statement, Archbishop Williams High School officials outlined steps the school was taking in response to the crash. At 1:30 Monday afternoon, the school will hold a prayer service for all students. Administrators have canceled all after-school activities and athletic events for Monday, and grief counselors will remain available throughout the week, the statement said.
Volonnio said about 50 students sought counseling the school provided at its chapel Sunday afternoon. He paused as he remembered his personal connection with the four students involved in the crash.
“These are great kids, involved kids,’’ the principal said. “And we now need to make sure our students have the resources so they can process this together.’’
Astead W. Herndon can be reached at astead.herndon@globe.com Follow him on Twitter @AsteadWH. Nicole Fleming can be reached at nicole.fleming@globe.com.
