A fire that damaged three stores in Northwest San Antonio early Friday morning has been ruled as arson.

The fire started around 12:30 a.m. at Nancy's Hair and Nail Spa at Bandera Road and Stonecroft.

Arson investigators said someone threw an incendiary device through a window, starting the fire.

The flames fizzled quickly because there was already plenty of water on the fire even before fire fighters arrived.

"The sprinkler system was going off and contained the fire to the business of origin, and we were able to put the fire out pretty quickly," said Captain Bryan Norris, with the San Antonio Fire Department.

The sprinklers left a big mess at the AT&T store and SportClips on either side of the salon.

Both were left with soggy store fronts, but crews used squeegees and dryers so the stores could open.

The nail salon also had fire damage.

"We have water everywhere, but the main damage is the windows and the portion right here. All the computer and paperwork and stuff are burned up," said Oanh Duong, whose father owns the salon.

She said her family was just thankful it wasn't worse.

"Luckily, most of the supplies we keep are in the back, so since the water put the fire out in time, we (didn't) have to deal with any more damage," she said.

The family hopes to reopen the salon in a few days.

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