BALTIMORE >> A day after a massive Baltimore house fire killed six children and injured their three siblings and their mother, classmates of two of the victims turned lockers into makeshift memorials Friday as a shocked community mourned.

One 12-year-old, Chloe Seergae, left a glass bird on the locker of her friend who had perished, saying that was “to keep their spirit alive.” Others left notes, photographs and teddy bears to remember those who died.

Six of the family’s nine children were killed, while their mother and three of her other children managed to escape with injuries, Fire Department spokesman Roman Clark said of Thursday’s fire in the city’s northeast.

He said the children killed included two boys ages 9 months and 2 years old, 3-year-old twin girls and two more girls ages 10 and 11.

The children’s mother, Katie Malone, and two boys, ages 4 and 5, were hospitalized in critical condition Thursday. Clark said an 8-year-old girl who had helped rescue her younger brothers was in “good shape.”

At the small, tight-knit charter school where the two eldest girls were students, families said they were devastated Friday.

“We’re a family here,” said Renata Seergae, Chloe’s mother. “It happened on such a large scale, there was no doubt in anyone’s mind that we are all going to get our kids through it and help out this family as much as we can.”

Chloe described her friend as kind, caring and fun. She loved Hamilton, the Broadway musical, and celebrated the Founding Father’s birthday each year just as she had done on Jan. 11, one day before the fire.

“She likes to laugh a lot,” Chloe said. “She was very nice to everyone; everyone was her friend. You could never get mad at her, because she was always so nice.”

Chloe said her friend was close to her siblings, and sometimes brought family photos to school to show to classmates.

Firefighters encountered heavy flames on all three floors when they were called to the home about 12:30 a.m. Thursday, Clark said. The firefighters had to attack the blaze from outside, he added, noting the third floor collapsed and the second floor partially collapsed from the fire.

Robert Spencer said he often saw children playing on the porch of the home, located across the street from his. When he looked out the window early Thursday, the home was in flames. Though he ran toward the fire, it was so big and hot he couldn’t help.

“I heard the kids crying. My daughter heard them. They said: ‘Help, help,’ and you know, couldn’t save them, couldn’t save them,” Spencer said. “There was just too much fire there.”

It was so hot that parts of a car parked out in front of the house had melted.

Investigators are now seeking clues to the cause of the fire.

William Malone, the father of the children, told The Associated Press he was away at work at the time of the fire.

“I’m still in shock to be honest,” said Malone, reached by phone at a relative’s home.

Democratic Rep. Elijah Cummings said Katie Malone has worked as a special assistant in his Catonsville district office for nearly 11 years.

“My staff is a family and this unimaginable tragedy is shocking and heartbreaking to us all. I again ask for your prayers,” said a statement from Cummings.