Nearly 35,000 customers in a large swath in Pinellas County from St. Pete-Clearwater International Airport to the Historic Old Northeast neighborhood were without power today, according to a Duke Energy outage map.

As of 11:40, an hour and 40 minutes after the outage began, all customers had regained power, according to Ana Gibbs, a Duke Energy spokeswoman.

Gibbs said the outage was caused by problems with three substations near the St. Pete-Clearwater airport. Duke is still investigating the exact cause.

Duke remotely rerouted customers’ power until the substations were restored. At the peak of the outage, 34,402 customers didn’t have power.

A Duke Energy substation located at 5400 Ulmerton Road in Largo, was one of three substations which had problems Tuesday morning that left about 34,000 Pinellas County customers without power for one hour and 40 minutes. [ DOUGLAS R. CLIFFORD | TImes ]

At the Tampa Bay Regional Resiliency Coalition’s first annual Leadership Summit in the Hilton at Carillon Park, the room went dark during a morning networking break. Emergency lights kicked on seconds later, but the microphones had stopped working. U.S. Rep. Charlie Crist took the stage and spoke about climate change without amplification — or his trademark fan blowing.

Outages also affected the Pinellas County Criminal Justice Center on 49th Street N.

Six schools lost power for about two hours: Bayside High in Clearwater, and Northeast High, Meadowlawn Middle, Sexton Elementary, New Heights Elementary and Lealman Innovation Academy in St. Petersburg. Power on all those campuses was restored by 11:45 a.m., and there were no major interruptions to instruction, lunches or other school operations, said district spokeswoman Isabel Mascareñas.

Pinellas deputies and police in Pinellas Park directed traffic at intersections that had power knocked out.