ZEPHYRHILLS — It was supposed to be a celebration at Skydive City in Zephyrhills on Saturday. There was a band and a barbecue, and a man who planned to celebrate his 80th birthday by jumping out of a plane with family and friends.

But there was too much wind, and the jump was canceled.

Earlier, around 10 a.m., a separate group of about 22 sky divers went up in a plane, according to manager David T.K. Hayes. Two of them from Iceland were found dead at 7:30 p.m. Saturday by Pasco County sheriff's deputies after an all-day search, according to spokeswoman Melanie Snow.

"Our helicopter was able to get a visual from the air," she said. "They were found very close to each other south of the airport off of Yonkers Road."

The sky divers were identified as student Andrimar Pordarson, 25, and instructor Orvar Arnarson, 40.

Arnarson was a "very experienced" instructor who has done thousands of jumps. Pordarson was on his eighth sky dive, Hayes said.

Earlier Saturday, before authorities got involved, Skydive City planes started a search, because it's rare for a sky diver to be missing for more than 30 minutes, Hayes said. "I've been doing this 17 years and I've never had anyone missing for more than two hours.''

The company used a skydiving plane — a De Havilland Otter — as well as a Cessna and two other private aircraft, said Ryan Lee, a Skydive City pilot.

"Thirty minutes (of searching) goes by, and then it goes to the next level of response," Lee said.

Hayes said he notified Zephyrhills police, and then it became a county issue. They checked the usual areas, including a baseball field and a nearby flea market, but found nothing.

"It's a risk we take," said Eric Hildebrand, referring to the jumpers' fate. "It was windy, but not unreasonable."

Hildebrand jumped in the flights before and after the one carrying the men who were later found dead. Everyone else on the flight made it to the ground safely.

Before the bodies were recovered, searchers looked for clues using video taken by other jumpers who left the plane around the same time. The men were not doing a tandem jump and Pasco County sheriff's deputies were uncertain Saturday whether their parachutes ever opened, said Snow, the spokeswoman.

She said sheriff's deputies searched using a helicopter and all-terrain vehicles Saturday evening in a widespread area mostly south of Zephyrhills Municipal Airport.

One of the sky divers wore a white jumpsuit, the other a white and black jumpsuit. One of their parachutes was green and white, while the other one was blue and gray.

At 7 p.m., a Pasco Sheriff's Office helicopter landed on the field at Skydive City, after covering nearby areas for a few hours. A group of people, including a woman with the words "Skydive Iceland" on her pants, looked on. She put her hands to her face while she watched. The group followed Hayes and sheriff's deputies into the office at the skydiving center. Hayes and the deputies outlined a search plan, and the helicopter took off again.

The helicopter crew saw the pair soon afterward.

Hildebrand, a former instructor at Skydive City who jumps on weekends, said the men used square parachutes that could maneuver against a headwind. He said the Sheriff's Office had an infrared detector on the helicopter to pick up body heat.

During the daylong search, people sat around in pockets waiting for news.

Frank Van Gelder, 64, said he visits Skydive City twice a year. He designs accessories and technical equipment for parachuting. He said jumpers generally have what he called a "piggy bag" on their backs. It has a regular chute and a backup. He said the parachutes are made of nylon and generally float in water. There are safety procedures as well that most sky divers know, such as hugging yourself to protect vital organs if you are headed for a tree.

Gelder said in his 40 years of jumping he could count on one hand the deaths he's witnessed. Generally, sky divers open a main chute around 3,000 feet, and if something goes wrong they can "cut away" the main chute by pulling a safety device attached to the pack.

An automatic reserve chute should open around 700 feet, he said.

Snow said the department would investigate whether the chutes used by the two men opened.

Gelder recalled one group jump when two participants hit each other in midair. One man was knocked unconscious, said Gelder, who glided over and pulled the man's chute. "We are a community," he said, "and we look out for each other."

The closer to the ground you are, the more dangerous it would be to try and save someone in that situation, Gelder said. "I could try to help, but I might die myself."

Staff writer Dan Sullivan contributed to this report. Contact Jon Silman at (727) 869-6229 or jsilman@tampabay.com.