Colorado Springs firefighter say a blaze that has damaged two detached garages at 2519 North Nevada Avenue in Colorado Springs Wednesday has been ruled arson.

The fire started just before 9 p.m. Wednesday.

John Protsman's quiet night exploded into activity when flames started climbing up the walls of his neighbor's garage.

"It's scary to think that anyone could go by and purposely throw something [flammable]."

That possibility is under consideration as fire investigators piece together a what led up to the blaze, which they are calling “incendiary.”

"Basically it rules out those causes that are accidental or natural,” said Colorado Springs Fire Marshal Brett Lacey on Thursday. The fire began on the outside walls of two detached garages in the neighborhood near Penrose St. Francis Hospital.

"Fire can spread very rapidly between buildings, especially communicating among fences and vegetation," Lacey said.

Suspect descriptions have not been provided, but John Protsman has seen those he'd consider suspicious.

"We do see some odd people come down that alley that you watch for," he said.

Protsman said he'll continue to watch for the sake of his neighbors who now know what it's like to have danger in their own backyard.

"I'm just glad they're all okay,” he said.

Fire officials estimate about $4000 worth of damage was done to the garage. The investigation is ongoing.

To report any fire-related activity that may be suspicious the CSFD Investigations Unit can be reached at 385-7292.