An explosion and fire rocked a Denver apartment complex Thursday morning.

"Like something big fell down the stairs it sounded like and then pops started happening, I don’t know the whole upstairs floor was on fire,” said Sophie Noorts, who called 911.

It happened at the Parliament Apartments on Quebec Street, in the Denver Tech Center, around 8:10 a.m.

The Denver Fire Department told Denver7 when firefighters arrived they found two apartments on fire, with explosions happening inside one of the units.

"It just escalated really, really quickly and then with the pops, pops, there were probably 15 or 20 pops that you heard you could see shooting flame coming out, so you would think, is this ammunition?” said Kimberly Moran-Blad, who witnessed the fire.

Two people were taken to the hospital -- a firefighter and one suspect -- according to Denver Fire Dept. spokesperson Louis Cedillo.

Cedillo said investigators are looking for one woman who may be connected to the fire.

Witnesses also told Denver7 that two people who lived in the apartment that was exploding, a man and a woman, had serious burns but the victims left before authorities arrived.

Hash oil explosion at the Parliament Apts this AM. Two people seen running from scene pic.twitter.com/QldUcTyx7v — Melissa Krol (@DenverNewsie) May 12, 2016

Cedillo said the fire is being investigated as a hash oil explosion based on evidence found at the scene.

Witnesses and neighbors told Denver7 the people in the apartment were making hash when the explosion happened.

2 units on S Quebec st with major damage after explosion due to possible hash oil extraction. @DenverChannel pic.twitter.com/uwFOdbexaj — ttyszka (@ttyszka7) May 12, 2016

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