File photo.

Federal authorities Friday announced a reward of up to $25,000 for information leading to the arrest and conviction of whoever sparked a spate of arson fires that caused tens of millions of dollars in damage at construction sites in University City and Torrey Highlands nearly 14 years ago.

The series of non-injury blazes — officially deemed domestic terrorism – – began about 3 a.m. on Aug. 1, 2003, when a five-story apartment building under construction just east of University Towne Centre mall went up in flames in spectacular fashion.

Firefighters arriving at the planned site of La Jolla Crossroads Garden Community found the conflagration too intense to battle directly. Instead, they evacuated surrounding area and protected nearby structures while letting the wooden framework of what was to be a 200-unit structure burn to the ground.

At the height of the blaze, flames shot as high as 100 feet into the air and sent a 10-story crane toppling. Officials set the monetary losses at $50 million.

Seven weeks later, a rash of early-morning arson fires destroyed four partially built homes at two construction sites northeast of Carmel Valley. The Sept. 19 blazes on Primrose Way and Rabbit Ridge Road caused an estimated $3 million in property losses.

Banners left behind on both occasions bore anti-development slogans — including “environmental murder” and “nature demands justice” — along with the acronym “ELF.”

One of the handwritten signs, about 12 feet long and draped across a patch of graded dirt at the site of the first fire, proclaimed: “IF YOU BUILD IT — WE WILL BURN IT — THE E.L.F.’s ARE MAD.”

Earth Liberation Front — a shadowy activist group that for 25 years has fought urban sprawl and perceived environmental threats with high-dollar acts of vandalism — soon claimed responsibility for the San Diego fires. The FBI took charge of the case because the crimes are considered instances of homegrown terrorism.

Anyone with information about the case was asked to call the federal agency at (800) 225-5324 or contact it online at tips.fbi.gov.

—City News Service