Multiple units in a Gwinnett County townhome community were damaged on Saturday after an unattended charcoal grill started a fire that spread through the building, fire department officials said.

Fire crews were sent to a townhome along Oak Glenn Drive in Duluth after a caller reported seeing a blaze coming from the back porch of the house, Gwinnett fire spokesman Capt. Brian Gaeth said. When they arrived, the left side of the four-unit townhome was consumed with heavy smoke and flames, he said.

Crews were met with intense heat when they tried to enter the second floor of the home, so they fought the blaze from outside the building. When the fire was under control, they entered the townhome and continued to tamp down the flames.

Fire officials determined the source of the blaze was a charcoal grill on the back porch of the townhome, Gaeth said. A resident told officials they had been grilling earlier in the day and thought they had extinguished the grill. The resident was not home when the blaze started.

Two of the units sustained heavy fire damage, and the other two had smoke damage, Gaeth said. It is not clear if anyone was injured in the blaze, but Gaeth said two family pets were rescued from the fire.

A GoFundMe has been created to assist one of the displaced families with the cost of housing and replacing their belongings.