Meanwhile, investigators had not yet officially determined a cause for the fire, but they were leaning toward blaming recent installation of heat tape on a roof gutter of the Vivint complex, near 500 South and 500 West.
"They had put heat tape on the roof to avoid icing issues, but it is a sheet metal roof and there's foam insulation underneath that we're thinking apparently just got too hot," Cullimore said.
A firm damage figure was still being developed, but Cullimore said, "It easily will be in the millions [of dollars]. About 400 to 500 computers inside were destroyed and there was a lot of water damage."
Extinguishing the fire, first reported about 9 a.m. Tuesday, took until late afternoon. Even then, it turned out, hot spots continued to smolder underneath the roofing. Lindon firefighters had to douse a small, short-lived flare-up in the insulation material again at 4:30 a.m. Wednesday, Cullimore said.
Several hundred employees of Vivint, a home automation and security company, were evacuated from the building and adjacent structures. Two employees complained of smoke inhalation and were treated by medics at the scene.
Joining Lindon firefighters on Tuesday were crews from neighboring Orem, Provo, Pleasant Grove and American Fork.