Boston will donate two surplus fire engines to a Haitian city that had its public safety equipment destroyed during the January 2010 earthquake. Cap-Haïtien, the country’s second-largest city, does not own a proper fire engine, Boston officials said. Throughout May, Cap-Haïtien suffered from many fires that had to be contained and allowed to burn out. There has been no loss of life to date from the fires. “We have extra firetrucks that we don’t use anymore, and this major city in Haiti has no firetrucks at all. We had to do something,” Mayor Thomas M. Menino said in a statement. The Dorchester House Multi-Service Center Inc. has agreed to help transport the engines to Haiti.