A 46-year-old participant in a pond hockey tournament on a Lake Minnetonka bay collapsed after his second game of the day and came to with the help of on-site medical personnel, but was soon stricken again and died, a teammate said Monday.

Gregory C. Riebe, of Crystal, died Friday afternoon while competing in the North American Pond Hockey Championships on Excelsior Bay. Authorities have yet to say what led to Riebe's death.

While covering the event for the suburban Sun Sailor newspaper, reporter John Sherman saw Riebe collapse following his second game that day with the Excelsior Brewing Company team.

Riebe "felt dizzy and collapsed," Sherman wrote. "His teammates, Jeff Cole and Jon Lewin, helped him to his feet, but then Greg dropped back to one knee."

Teammate and childhood friend John Klick said Riebe was unconscious for about "6, 7 seconds and he came back."

Emergency medical technicians (EMTs) staffing the championships "gave him water, and he ate a sandwich. … He was standing up, somewhat joking, saying he was tired."

About 30 minutes later, with the EMTs still at his side and "just as everybody was moving on … he went down and never came back."

Excelsior Fire Chief Scott Gerber, whose agency responded to the scene, said that "nothing happened during the hockey game, no trauma, no shot to the chest" before Riebe was stricken.

Klick said the family has been told that the medical examiner's office found that Riebe had an enlarged heart, but a determination of what led to the death was still pending.

"It's a real fluke," Klick said.

Amid all the black helmets that the Excelsior Brewing skaters had donned Friday, Sherman said, Riebe was wearing his gold Wayzata High School helmet from the late 1980s, when he skated for the Trojans and was their varsity captain.

"We were trying to bring in a ringer," Klick said in jest of his friend from junior high and high school.

Riebe's Twitter account notes that he was a marathon runner, and also enjoyed hockey, soccer, reading and "spending time with my wife [Kathryn] and kids [August and Emma]."

A funeral service for Riebe, who worked as a sales trainer with PSR Consulting, will be held at 11 a.m. Saturday at St. Philip the Deacon Lutheran Church, 17205 County Road 6, in Plymouth, with visitation one hour before. There also will be visitation will be from 5 to 8 p.m. Friday at the David Lee Funeral Home, 1220 E. Wayzata Boulevard in Wayzata.