HAYWARD -- Two people who jumped from a second-floor window were among 27 displaced Tuesday by an overnight fire at the Whitman Green Apartments, a Hayward Fire spokesman said.

A family's pet Chihuahua dog died in the fire, which broke out at 2:45 a.m. near Whitman Street and Cottage Park Drive, but no other major injuries were reported, said Hayward Fire spokesman Don Nichelson

Aarti Bhan, 30, lives in the large, gated apartment complex and said she and her husband were asleep in their second-story unit when she heard stones being thrown at her window. When she looked outside she saw a neighbor who lives in the unit below her screaming at her.

She soon noticed her apartment was filled with smoke so she grabbed her 3-month-old daughter and ran out the apartment's front door, she said.

But her husband and her 19-year-old brother were unable to follow her out and instead ran to a back window and jumped about 12 feet to the ground.

Her brother, Ritesh Bhan, said he injured his knee in the jump, but that his brother-in-law was not injured.

"When she opened the front door, the apartment filled with smoke," her husband, Shalveen Chand, recalled as he stood beside his brother-in-law wrapped in a gray blanket outside their badly burned apartment. "She ran out through it -- just went with her instinct. For me and him, it was too late. It was so smoked filled we knew we had to jump."

The couple's 3-month-old baby may have suffered smoke inhalation but was not treated by medical personnel, Bhan said. Regardless, Bhan said she was planning to take her daughter to a hospital to be checked out.

She also said she was thankful to her neighbor for waking her up.

"That lady was amazing," Bhan said. "I don't know what would have happened had she not (called out) to us."

Shortly after the blaze was reported, a second alarm was sounded but those crews were not needed, and the fire was under control by 3:16 a.m.

Two units in the two-story apartment building were damaged heavily, Nichelson said, though no estimate of the damage was given.

What started the fire was not immediately known, but investigators said one resident in the building turned on his stove and after walking away from it, came back to the kitchen to find it on fire.

The Red Cross was on scene to help the 27 displaced residents find housing on Tuesday.

Contact Natalie Neysa Alund at 510-293-2469. Follow her at Twitter.com/nataliealund. Rick Hurd at 925-945-4789 and follow him at Twitter.com/3rdERH