Veteran stuntman Christopher Sayour was in serious condition late Tuesday after falling from a tower during the filming of the WB Network drama "Smallville" in Vancouver.

Sayour, 35, the stunt coordinator for the show and primary stuntman for "Smallville" star Tom Welling, was badly injured in what one source described as a "freak accident" during filming Tuesday morning on location near the township of Langley.

In a statement, Sayour's family said that he had suffered "multiple fractures and internal injuries during the filming of a stunt sequence." The family also asked that the media "respect our privacy as he undergoes various procedures in the coming days."

Sayour was airlifted to Royal Columbian Hospital in nearby New Westminster in critical condition but was upgraded to serious by Tuesday evening.

"Our thoughts and prayers are with Christopher and his family during this difficult time and we wish him a full recovery," the WB and Warner Bros. Television, which produces the teen Superman drama series, said in a statement late Tuesday.

Diane Blaine, a spokeswoman for the local Langley detachment of the Royal Canadian Mounted Police, confirmed that Sayour had suffered "significant injuries" after falling 37 feet from a tower.

Blaine said the police investigation found no grounds to suspect foul play and concluded that Sayour had accidentally fallen while performing a stunt.

The "work safety" investigation was then turned over to the British Columbia branch of Workmen's Compensation Board, which investigates Canadian workplace accidents. Calls to the WCB were not returned by press time.

A representative of Stunts Canada, the Vancouver-based association of professional stunt coordinators and performers, had no comment when asked about the accident. Production on "Smallville" halted after the accident but is expected to resume today, sources said.

"Smallville" shoots have caused some concern recently among locals.

Special effects sequences were the cause for alarm last week, according a report on the Web site of the Vancouver Sun newspaper. SkyTrain, Vancouver's rapid transit system, issued a public advisory to alert commuters that the loud blasts they heard during their commute were not terrorist bombs but "Smallville" production crews.

A SkyTrain official told the Sun, "The filming poses no risk to travelers, but given the recent terrorist attacks in London, the company felt it was prudent to warn its customers."

Sayour has been the stunt coordinator for "Smallville" since the series debuted in 2001. He also was a stuntman in such feature films as "I, Robot," "Star Trek: Nemesis," "Dr. Seuss' How the Grinch Stole Christmas" and "Three Kings" and the Showtime telefilm "Reefer Madness: The Movie Musical." Sayour also has had bit acting parts in 2002's "The Time Machine," 1997's "Batman & Robin" and the Sci Fi Channel series "Stargate SG-1."

"Reefer Madness" executive producer Kevin Murphy, now a co-executive producer on ABC's "Desperate Housewives," recalled Sayour going the extra mile to complete a shot that called for him to jump off a balcony into a stairwell in the guise of a zombie bandleader.

"It's a big, popping, eye-candy moment," Murphy said. "The whole stunt team was doing this at 4 o'clock in the morning after 11 hours of stuntwork, and he was doing it with professionalism and a smile. I look forward to working with him again when he's better."

Etan Vlessing reported from Toronto; Kimberly Speight reported from Los Angeles. Sheigh Crabtree in Los Angeles contributed to this report.