SURREY, B.C. - Fire investigators say fireworks landing on a balcony is the strongest hypothesis as to what caused a major apartment fire on Halloween night.

Twenty-four units had to be evacuated the night of Oct. 31 when the fire started at around 11:30 p.m. on 150th Street near 105 Avenue.

Flames and smoke could be seen pouring out of a suite on the third floor of the building.

"The investigation revealed that the fire did start on the balcony and we've ruled out as many sources of ignition that could be possible in that area such as electrical or gas," said Surrey Fire's Asst. Chief Jason Cairney.

"There were some witness statements that did indicate that they saw fireworks in that area and potentially landing on balconies, so it's a strong hypothesis that it could be a firework that did start that fire, but we can't confirm that 100 per cent."

Witnesses told CTV News there were fireworks going off in the park next to the apartment complex. One resident said they were so loud it sounded like they were inside her apartment.

Two dozen units were evacuated the night of the fire and residents from 13 of those were due to return Tuesday.

Maria Marshall lives in the building and told CTV News she was set to come back but her apartment failed an air quality test, so will be staying in a hotel for a few more nights.

About six units were significantly damaged and residents won't be able to return for an extended period of time.

"We are still actively involved with partner agencies such as the Red Cross and BC Housing to attempt to find longer term solutions for those affected," Cairney said. "It has been confirmed there is asbestos in that building so that will slow down the restoration timeline."

The fire investigation report will now go to Surrey RCMP to determine if any charges will be laid.