The fire happened just before 3 p.m. Friday afternoon in the 2900 block of Gross Avenue near St. Kaplan Woods Way.
One person was taken to a hospital for treatment from smoke inhalation.
The townhome is one of five units. Three units sustained damage.
Firefighters credited the firewall for playing a big role in stopping the fire from spreading to other units.
"Outside of the response from the fire department today, that fire wall made the day," said Battalion Chief Edward Barrett of Wake Forest FD. "It saved the day. It was very effective in isolating the fire to the units that the fire started in."
MORE: @RaleighFire, @NewHopeFire, @RolesvilleFire & Eastern Wake called for second alarm because of weather. The heat forcing crews to rotate every 20 mins. @NDMS__Raleigh providing this bus for A/C and water breaks. @ABC11_WTVD pic.twitter.com/kDMtSd8jsF— Jonah Kaplan (@KaplanABC11) June 28, 2019
Heavy smoke could be seen coming from the roof, which was heavily damaged.
Patrick Lewis, a neighbor said he worked to make sure everyone was alerted. He went to every home, banging on the doors to make sure people got out, including on the door of the man that was sent to the hospital
A number of @WakeForest_NC firefighters still on scene of this fire. Fire appears to have started on backside of the townhomes. One person taken to the hospital for smoke inhalation. #ABC11 @wakeforestfire pic.twitter.com/z9ndKKajc0— Josh Chapin (@JoshChapinABC11) June 28, 2019
"I went knocking on the doors," Lewis said. "Some of the folks were already coming out of the doors, and I was trying to yell ... to get out, get out, and they said we still got a few animals and I said, 'You still got to get out' -- your whole roof is on fire now."
One cat is missing from the unit where the person suffered from smoke inhlalation.
"I went over there, banged on the door and banged on the door and no response and I finally got a response and it was a teenager, who was home," Lewis said. "He was home alone and never knew there was a fire going on.
"I just do what anyone else would've done in the situation. I have kids and all these homes are built the same," Lewis added. "All I wanted to do is try and help some people, that's all I wanted to do."
New Hope Fire Department, Northen Wake Fire Department, and Wake Forest Fire Department were first on the scene. They were soon assisted by Wake Forest Police, EMS, Rolesville Fire Department and other agencies.
The fire remains under investigation but appears to have started somewhere on the backside of a row of townhouse units.