The Ontario Ministry of Labour has laid 13 charges against three companies and one engineer in connection with the fatal stage collapse at an outdoor Radiohead concert in Toronto last summer.

A drum technician for the band was killed, and three others were injured, after a massive outdoor stage at Downsview Park partially collapsed hours before the popular U.K. band was to play for a sold-out crowd of 40,000 people.

The ministry said on Friday that Live Nation Canada Inc., Live Nation Ontario Concerts GP Inc., Optex Staging & Services Inc., and an unidentified engineer were all facing charges under the Occupational Health and Safety Act.

According to the ministry, Live Nation Canada and Live Nation Ontario failed to comply with a specific subsection of the act dealing with a building or structure's capabilities in supporting "any loads that may be applied to it."  Each is charged with four counts.

The ministry said the engineer is facing one charge of "endangering a worker, as a result of his advice that is given or his certification that is made negligently or incompetently."

Toronto-based Optex is facing four charges also related to the stage’s structure and stability.

 The company has built stages and grandstands for the Edgefest and Lollapalooza festivals, as well as shows by U2 and Bon Jovi.

A first appearance is scheduled at the Ontario Court of Justice in Toronto on June 27.