A youth wielding a hatchet and a pellet gun scooped $12,000 from a safe at Garfinckel's department store here yesterday, but was seized after a furious struggle with store personnel who swung chairs and a blackjack to subdue the suspect, according to police and witnesses.

Police said the incident began on the eighth floor of the downtown store about 5:15 p.m. when the youth approached the cashier's booth and smashed one of its windows with a hatchet.

Unable to crawl through the shattered pane, police said, the bandit placed his gun against the back of credit manager Paul Luttkus, and as about 40 startled empoloyes working nearby dived to the floor, he demanded to be taken to the safe.

Halting before a locked door, Luttkus claimed he could not open it, according to witnesses. But the bandit found an open door, reached the safe, scooped cash into a blue knapsack and turned to go.

By the time he reached the elevator bank, according to witnesses, an alarm had been sounded and store manager Harry Wortman, 60, and purchasing agent Girard Dary, 61, had arrived.

A struggle ensued inside an elevator car, witnesses said, with the youth swinging his hatchet and chopping at chairs brandished by Dary and Luttkus.

Wortman finally grabbed the bandit about the neck, and as they dropped to the floor, the money spilled from the knapsack. The struggle continued on the cash-covered floor of the elevator until security guard Jersey Green, 26, struck several blows with his blackjack, subduing the youth, according to the witnesses.

"I haven't had a fight like that since Guadalcanal," said store manager Wortman, a retired Marine Corps colonel who served in both World War II and the Korean War.

Police said they arrested a 16-year-old youth and took him to D.C. General Hospital for treatment of scalp lacerations.