Dennis O. Simmonds was a hard-charging police officer who loved his job, though it often put him in danger, running down alleyways after gang members and into the Watertown gun battle with the alleged Boston Marathon bombers, in which he was wounded in an explosion.
The 28-year-old won the Boston Police Department’s highest honor for his bravery and was slated to travel to Washington in May to receive another award from the president.
But Simmonds died late Thursday night after a medical emergency in the gym of the Boston police academy in Hyde Park, according to Boston police Sergeant Michael McCarthy. He was on duty at the time, and had just taken his lunch break during in-service training.
“All he ever wanted was to be a policeman. He fulfilled his dream,” said Boston Police Commissioner William Evans. “As far as we’re concerned, he did it so well, and that’s why we’re all heartbroken. Great officers like him are tough to lose.”
That dream was a long time in the making, according to Simmonds’s father, also named Dennis Simmonds.
“As a little kid, he would say, though he could barely talk, ‘policeman!’ ” said the elder Simmonds. “When he heard sirens, he would try his best to pull himself out of his car seat . . . just to see the car.”
After graduating from college, Simmonds immediately enrolled in the police academy.
“I said, ‘We just paid for four years of college. Are you sure you don’t want to do something else?’ But he wanted to go to the police academy,” said Simmonds’s father.
Simmonds joined the department six years ago, and was assigned to the Youth Violence Strike Force, which deals with the city’s gangs, in 2012.
“These guys, they really care about the city, they really care about making the city safe,” said Evans. “Every night, they’re out on the streets of the city working hard on the violence and getting guns off the street.”
Simmonds’s job was hard on his mother, who did not like to see her son leave home in his vest or carrying his sidearm, said his father.
On April 19, Simmonds went to Watertown, where police engaged in a shootout with the two alleged Marathon bombers. One of the alleged bombers, McCarthy said, threw an explosive at Simmonds, who suffered a head injury in the blast.
Simmonds received the Schroeder Brothers Memorial Medal, the department’s highest honor, for his bravery. Evans said he was to travel to Washington in May to receive the Top Cop Award from President Obama.
“He was looking forward to it,” said Evans.
But Simmonds was not one to brag about the award, said his father.
“He didn’t like to be in the spotlight, so he didn’t showboat it too much. He was more enthusiastic about doing the job than the honors — getting out there, getting guns off the street, talking to kids on the street.”
Simmonds was a health nut and loved to do CrossFit, run road races, and play basketball, according to a law enforcement official who knew him. Simmonds was “the picture of health,” he said.
Police did not release further details about what medical emergency Simmonds suffered. His funeral arrangements have not been finalized.
Evans said Simmonds was not married. His mother and father are devastated, he said, and his tight-knit unit is mourning his loss.
Simmonds’s father said that his son was a “respectful, grab-the-bull-by-the-horns guy” who grew in the department because of his love for and skill at his job.
“I know the whole gang unit appreciates that they brought up such a great kid,” Evans said. “Between the Marathon bombing and his nightly work, he had all kinds of courage. He should be commended, and it’s a sad day for the city.”
Maria Cramer of the Globe Staff contributed to this report. Evan Allen can be reached at email@example.com. Jennifer Smith can be reached at firstname.lastname@example.org.