Onlookers watch as the Serenity House apartment building gets demolished earlier this week.

Final demolition of the Serenity Shop unexpectedly uncovered an underground tank, city officials said. David Garlington, city engineer and assistant public works director, said the tank was not recorded during the original investigation prior to demolition because the Serenity Shop was still open, making investigation of the area difficult.

The tank will be removed along with known tanks, including one once used to hold fuel to heat the apartment building. City officials this week meet with the subcontractors to mull pre-construction details of the new Civic Center.