DENVER — An explosion at gazebo next to an apartment complex startled residents and prompted an evacuation but caused no injuries.

The explosion happened at the French Quarter at Nine Mile Station apartments in southeast Denver around 7 p.m. Sunday.

Denver Fire Department spokesman Mark Watson told KUSA-TV (http://on9news.tv/1hLEEvq ) that the explosion and resulting fire had been contained to a free-standing gazebo that used to house mailboxes. Watson says the there is no danger to the surrounding structures.

The cause of the explosion and fire remains under investigation. Natural gas to the complex has been turned off while firefighters investigate.