He died in the service of his country on the Mall on the Fourth of July, and he was buried in an unmarked grave on the peaceful Manassas farm that, had he lived, would have been his retirement home.

To those who knew him, the black-and-brown U.S. Park Police thoroughbred was a finely muscled, handsome animal -- a little high-strung, but with a likable personality.

The 14-year-old bay horse had a heart attack and died while on Mall patrol just before the fireworks began, a sudden reckoning that seemed an appropriate reflection of his name: Random Choice.

News of the demise of the 1,500-pound animal was met with surprise and sadness throughout the elite 55-member U.S. Park Police Mounted Unit, where officers and animals are working partners and friends.

"He had a good life," said one officer who knew him. "I was really sorry to hear he'd passed away."

Random Choice was donated to the Park Service by Peter Flagg, a Wallingford, Conn., horseman who had shown him in running and jumping events. Flagg could not be reached for comment yesterday.

The horse, one of about 65 Park Police mounts in the area, was the first to die in about four years, officials said.

At 16 hands high, "he was a big, impressive horse," said Sgt. Denis Ayres, the corps' second-ranking officer.

Some mounts are gentle and adaptable; others are more flamboyant. Random Choice was one of the latter kind: "He had a personality," one officer said with admiration. The horse pranced and bounced the way thoroughbreds sometimes do, he said.

But "not everyone got along with him," Ayres recalled. "He walked on his toes a lot. A lot of people prefer a horse that is a little easier to walk."

His most recent regular rider, Officer Jim Watson, "worked perfectly with him," a fellow policeman said.

Watson, on the mounted force since 1976, had a quiet personality that meshed well with that of his horse, other officers said.

The two worked the beat for three years, covering downtown demonstrations and roaming through Rock Creek Park, where Random Choice was stabled.

The horse got along well with children, one officer recalled. "An outstanding police horse," Ayres called him.

Watson was on vacation last week, so Random Choice was assigned to another officer, Sam Graves, who, as it happened, is a friend of Watson. The horse died with dignity, Ayres said, quietly lying down rather than collapsing as Graves walked him down the Mall.

Graves was not injured, but "he was all shook up," a fellow officer said, and he was sent back to the Rock Creek horse barn to recover.

Watson is due back on duty today.

"It's quite a trauma when something like this happens," Ayres said. Horse and man develop a deep bond, he said, because most officers "spend more time with their horse than with their family."

No autopsy was performed because the horse was so obviously hemorrhaging, Ayres said. The horse's death was quick, and probably better than living to an old age and going lame, he said.

Random Choice was picked up from the Mall with a crane and was buried Friday in a section of Manassas Battlefield Park that the police use for their retired horses.

Said Ayres: "He did his part and his share."