Vernon residents were startled by an explosion Monday evening.
The loud bang was followed by flames seen coming from the top floor of the Arbor Lee Apartment building off Alexis Park Drive.
“I heard a loud boom,” Eric Draht said.
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Dept. Chief Scott Hemstad with Vernon Fire Rescue Services held a press conference in Vernon on Monday.
He said the call came in just before 7 p.m. Monday night.
The fire started on the balcony of one of the units, but soon spread into the attic.
Crews from BX and Coldstream fire departments were called in to help.
Because of the age of the building, it was not equipped with sprinklers.
Firefighters faced a difficult struggle, and at one point, could no longer fight the fire from inside.
When the blaze was finally extingueshed, crews found three family pets that had been hiding inside.
They were unharmed.
About 40 people are now out of their homes.
It has not been determined what caused the fire.