ROUGH CUT (NO REPORTER NARRATION).

STORY: A concert by the British rock band Radiohead was canceled after a portion of the stage collapsed during sound checks before the show on Saturday , killing one person and injuring several others, police said.

At least three people were seriously hurt in the accident, which occurred at about 4 p.m. local time at Downsview Park, about 5 miles north of downtown Toronto, local media reported.

Representatives for the concert's promotion company, Live Nation, were not immediately available for comment. Downsview Park officials had no comment on the incident except to confirm that the Radiohead concert had been canceled as a result.

Rehearsals and sound checks were being conducted at the venue when the collapse occurred, but the headline band Radiohead was not on stage at the time

Investigators were still unsure what caused the mishap.