The city of South Portland said it will conduct an internal investigation to determine how firefighters on Tuesday damaged a brand new, $1.1 million Pierce ladder truck during a training exercise.

The city said a crew of three firefighters were training in the rear parking lot of the Cash Corner fire station when the truck’s aerial ladder made contact with some power lines along Skillin Street, damaging portions of the truck’s electrical system, the city said in a written statement.

The surge of electricity also caused the truck’s front right tire to catch fire.

The three firefighters who were training with the truck were able to escape the vehicle and extinguish the flames.

Central Maine Power shut down electricity to Skillin Street so the fire crews could remove the truck.

Support staff from the truck manufacturer, Pierce, assisted fire fighters to use manual override systems on the truck to lower the aerial so the truck could be stored in an empty bay of the fire station.

Engineers from the manufacturer are expected to assist in troubleshooting the damage and determine a path moving forward, the city said.

In the interim, the city will deploy its 1996 ladder truck.

This story will be updated.

South Portland Fire Department’s new ladder fire truck, center, is out of service after it came in contact with electrical wires during a training exercise. (South Portland Fire Department Facebook photo)