OSAKA -- The head of Osaka Gas Co. admitted Friday that an error in a gas-pipe map the firm prepared is partly responsible for the fire that gutted Nakaza theater in the city's Dotonbori district.

Akio Nomura, president of the utility firm, admitted the mistake and offered an apology.

Four men were injured Monday when the closed-down historic kabuki theater in the main entertainment district caught fire.

The theater was established in 1653. The structure that burned down was constructed in 1948. A cinema was also set up in the theater in 1952. For decades, Nakaza was a symbol of entertainment in Osaka.