CHICAGO (CBS) — A warehouse that was supposed to be a key part of revitalization in the Avondale neighborhood was destroyed by a massive fire Monday night.

The fire started around 7:45 p.m. at a three-story warehouse in the 3000 block of North Rockwell Street. The first crews to arrive found flames on the second floor. The building was quickly engulfed.

“They made an interior attack, but the fire was too large at that time we got on the scene, and we told them to back out. We were concerned about the building. We could tell that the building had been rehabbed sometime in the past,” Fire Commissioner Jose Santiago said.

The fire was soon upgraded to a 2-11 alarm, bringing more than 100 firefighters to the scene.

The heat was so intense, part of the building collapsed in the blaze.

Ald. Deb Mell (33rd) said the warehouse was undergoing an extensive renovation.

“This building was really the start of something really great in this area. It’s an industrial area. So it was an old warehouse, and this gentleman bought it, put a lot of money in it,” Mell said. “It was beautiful in there, and he was in the process of getting tenants, so it’s really heartbreaking for the owner – I mean, I haven’t spoken to him. I’m trying to get hold of him – but for the neighborhood. It was going to be a spark.”

Mell said the owner was trying to bring in different food- and drink-related companies; such as a coffee roaster, a brewery, and perhaps even a chocolate-making company. Those dreams have been put on hold.

“This area has been neglected for a long time, and we’re not giving up on it. We really think it’s going to be a really cool space for our neighborhood, and for the city, actually. We want to bring jobs in this area, and we’re going to continue to work and do that,” Mell said.

No one was inside the building when the fire started, and no injuries were reported.

The fire was struck out around 10 a.m., but flared up again around 5 a.m., bringing firefighters back to the scene for about an hour Tuesday morning.

The cause of the fire was under investigation.