Investigators have determined that Saturday's three-alarm fire at the South Street Seaport was caused by electrical wiring catching fire underneath Pier 17.

Fire officials say the wires supply power to vending machines and lighting along the pier.

Flames broke out around 4 p.m. Saturday, just as hundreds of people were out enjoying the weather and attending a summer music festival.

Firefighters had to use chainsaws to remove some wooden planks to get to the fire and also battled the flames from the water.

The mall at the pier had to be evacuated, but was later reopened and the music festival was also able to continue.

No injuries were reported.