A building adjacent to the recently opened Union Market in the Florida Avenue NE warehouse district burned down last night after a two-alarm blaze broke out. The cause of the fire, which broke out about 10 p.m., is not yet known, though the building housed food wholesalers that deal to local businesses.

The building is at Fourth and Morse Street NE, the Post reported.

Union Market, a new food hall with some 40 gourmet vendors and eateries, was not damaged in the fire, which took several hours to extinguish. The market opened today at is normal time.

The fire, though, was more tricky to extinguish than firefighters expected, with the warehouse’s thick concrete walls making it difficult for crews to enter the building, according to WUSA9.