Henry Langworthy was unloading a beehive in Silver Spring yesterday when the hive fell from his hands and hundreds of angry honeybees swarmed over him and under his protective gear.

The 50-year-old Langworthy, a beekeeper for about two years, tried to run but collapsed as the bees stung him around the neck. He was pronounced dead two hours later at Montgomery General Hospital.

If authorities confirm that he died from the bee stings and not a heart attack, Langworthy, a civilian scientist at the Bethesda Naval Hospital would be one of only 50 Americans who die each year from insect stings.

Langworthy, who lived at 14110 Parkville Rd., Rockville, was trying to move two beehives into a friend's back yard at 5:15 a.m. when the accident occurred.

Immediately after the hive fell, the friend, Jack Machlin, went into his house at 15817 Thompson Rd., Silver Spring, to get a broom. When he returned, police said, he found Langworthy lying unconscious about 30 feet from where the accident occurred.

Police speculated that Langworthy either tripped and fell or had a heart attack after the bees began to sting him. Both Machlin and police officers tried to revive Langworthy.

Langworthy suffered a heart attack eight years ago but had been physically fit since then, according to police.

Karl Kronbein, senior scientist in the Smithsonian Institution's entomology department, said yesterday that deaths from bee stings are often misdiagnosed as heart attacks. Suffocation and allergic reactions to bee venom kill sting victims more frequently than heart attacks, he said.

"A number of stings on the neck can cause so much swelling as to cut off the supply of air to the lungs," Kronbein said.