Those who witnessed a 14-year-old surfer lose his arm in a collision with an incoming dory boat off Cape Kiwanda say the accident resulted from a series of unfortunate circumstances in a spot with increasingly heavy ocean traffic.

Cole Ortega, 14, of Bend was listed in serious condition Monday night at Legacy Emanuel Hospital, where he taken by helicopter after Sunday's accident near Pacific City. Another surfer found the severed arm and brought it to the beach so it could be taken with Ortega to the hospital.

Tillamook County Sheriff Todd Anderson said his department is investigating whether to cite anyone for the incident. A sheriff's deputy, Charles Reeder, said the area where the collision took place has become busier in recent years.

"You've got windsurfers [and] surfers. You've got hang gliders [and] people waiting on the shore line. You've got all kinds of different user groups down there," Reeder said Monday. "You've got swimmers, too, and kayakers. And when you put all of those together in one spot, it doesn't always work out, like we found out yesterday."

Dory boat driver Darrell Martin, 55, of Beaver could not be reached for comment, but a witness who said he spoke with Martin on the beach told The Oregonian newspaper that Martin was in shock and expressed extreme remorse.

Dories have been launching and landing directly off the beach for decades, part of the local tourist and fishing lore. But surfers and other users have started to appear there in greater numbers.

A witness, Ned Brewer, 51, of Portland, said he has been surfing at Pacific City since 1992. He said Sunday started out with a small swell, ideal to launch the dories, and most of the surfers were actually away from that spot, working beach break waves.

After the dories had launched, he said, the swell rose dramatically, luring the surfers back to catch the best waves in a channel where the boats launch. The high swell also meant that dories needed to start coming into shore, bringing everyone together.

He was in a line of about 20 surfers when suddenly a friend appeared next to him, saying he was almost hit by a boat. The surfer told Brewer, "I could feel the prop go over my legs."

Moments later, there was yelling.

"I heard someone scream, 'Oh, my god!' and I started paddling toward him," Brewer said.

Ortega is an accomplished athlete, a champion in slopestyle snowboarding and other sports. The Bend Bulletin reported that he finished first overall in his age group in slopestyle at a national meet last winter at Copper Mountain, Colo.

"I was stunned," Hans Hibbard, Ortega's coach, told KTVZ-TV. "Cole's such an active and athletic kid. It's difficult to think of him being in this position without actually seeing it — it's hard to imagine."