EMBED >More News Videos Gas leak at the Municipal Courts Building in downtown Houston.

HOUSTON, Texas (KTRK) -- The Houston Municipal Courts Building was evacuated today after a smelly gas cloud moved through downtown Houston.Harris County Pollution Control sent crews out to investigate the odor but they were unable to detect anything. Pollution Control said they believe the smell may have come from a mobile source, like a train.Police and firefighters arrived at the scene on 1400 Lubbock, where some reported feeling woozy. No one was transported to the hospital.The building was evacuated twice before people could finally go back inside.According to HFD, it received multiple calls Wednesday morning about a gas odor across the northeast side of the city.The calls first came from Wallisville Road around 9 a.m.