UPDATED 05/16/11 1:27 p.m.

AURORA, Ill. (CBS) — Residents believe an overturned candle might have sparked the fire in Aurora that killed six people — including four members of one family — over the weekend.

But investigators say it will take time to determine an official cause.

The fire broke out just after 4 a.m. Sunday morning in a three-story stucco apartment building in the 700 block of Claim Street.

The fire appeared to start in a first-floor apartment. An open door to a stairwell acted like a chimney and vented deadly smoke and flames throughout the building.

Micaele Perez and her husband, Francisco Marcos, died along with two of their sons, kindergardener Francisco Jr. and fourth-grader Jose Francisco. 

A third son, 12-year-old Teodoro, was hospitalized for smoke inhalation and is the famly’s sole survivor.

“Emotionally he is destroyed,  what can I say?  He lost his whole family, ” relative Mali Velezquez told CBS 2’s Vince Gerasole. 

The other two fatalities in the fire — an infant and a 43-year-old woman — have not been identified. An Aurora city spokesman says that may not happen until all of the victims’ autopsies have been conducted, possibly Tuesday.

The fire traveled so quickly that those on upper floors jumped from windows to safety, because it was their only way out.

In addition to those killed, four others, including a girl about 2 who was later airlifted to Loyola Medical Center, were also injured and transported to Mercy Medical Center, according to Ferrelli.

Two other victims were treated and released from Delnor Community Hospital in Geneva.

Six other people were also taken to Rush-Copley Medical Center. Ages and genders on the injured were not immediately known.

East Aurora School District 131, the American Red Cross and the Emanuel Baptist Church are collecting donations for all families impacted by the fire. All donations may be dropped off at the church, at 742 Claim St. in Aurora.

At nearby Brady Elementary,  where the Marcos brothers attended school,  grief counselors have been speaking with the young students who’ve taken these deaths quite hard.

 “We see them come in,  we see them with all kinds of stories, and  we just want to make sure they have clarity, ” said principal Francisco De Los Santos. 

The Sun-Times Media Wire contributed to this report.