"They have reports of multiple patients due to a structural collapse of the residence," a spokesman for the Houston Fire Department confirmed to the LA Times.
Authorities say the second floor of the garage "pancaked" onto the first floor, injuring victims in both sections of the parking structure.
At least 30 victims were rushed to area hospitals, with some reports indicating as many as 50 victims. Overall police say over 100 people were hurt, including six children.
The collapsed building was not a parking garage in the traditional sense, but a small, private, two-story structure located behind a residence. According to a letter distributed to neighbors, the garage was host to a "religious celebration" with 150 expected guests, music and dancing.