Kalif Rehman lives three doors down from where the fire started and didn’t think much of it at first, but then he heard sirens wailing, a crowd forming and saw thick smoke outside his front door.
He told News: “I saw a lot of lanterns on the street. I opened the door and there was smoke all over the road.
“A small crowd gathered and watched the smoke coming from the roof. Everyone was shocked and scared. I saw embers in front of my house, and the smoke was heavy and thick.
“I was afraid for my own health. I hid my cat because I thought the chemicals would damage her lungs.’
Mr Rehman joined the crowd as 20 firefighters from Southsea, Havant, Cosham and Portchester tried to put out the inferno and check on nearby residents.
“I saw a lot of water being used, but the fire was still growing,” he added. “Everything was on fire in the house. Flames sputtered like a geyser.”
Max Lewis, owner of nearby Ace Furnishings, said he found out about the fire through frantic phone calls and text messages from his friends.
He saw hell as he parked his car and ran towards it from Percy’s way. “I flew here and the road was blocked off,” Mr Lewis said. “The roof was on fire and the flames were spreading.
“Everyone thought that they would set the neighboring buildings on fire. It was 10 to 15 feet high, with flames spreading everywhere. “I was really afraid it would go to other places.”
Fawcett Road resident Annamur Rehman, 54, received video footage of the fire and a panicked phone call from his wife.
The owner of Bombey Bicycle Club, on Elm Grove, said: “There was a smoke club. It was very scary. I was told that people from other buildings may have had to be evacuated due to chemicals and smoke.
“At 1am the firemen were still there. Hoses were running down the street. When I woke up, the people were still there. I panicked a bit at the time.’
Emergency crews from Hightown and Fareham attended overnight as crews weakened. The Southsea crew left at 4am today.
A standstill was called at 6.07am before firefighters returned to check for hot spots. A spokesman for Hampshire and Isle of Wight Fire and Rescue Service said officers from Hampshire Constabulary and the electricity company were at the scene to cut power to the first floor as the roof collapsed.
A spokeswoman for Hampshire Constabulary confirmed the site was believed to be a cannabis factory. She said: “Officers attended and a suspected cannabis factory was located on the premises.
“As a result of the fire, no one was injured. The incident is being investigated. At the moment, there have been no arrests.”