REUTERS/Stringer
The baby and a 40-year-old man are the only confirmed deaths from the building, a complex of towers whose floors pancaked down onto to each other when the 6.4 magnitude tremor struck just before 4 a.m. (2000 GMT), at the start of a Lunar New Year holiday.
The quake, initially reported as a magnitude 6.7, was centered 27 miles (43 km) southeast of Tainan, a city of nearly 2 million people.
Photos of a building near collapse as well as several photos of buildings that came down surface on Twitter shortly after. The local government has formed an emergency response team, Express reported.
"Collapsed buildings reported in Tainan, with rescue workers arriving on scene," Taiwan's China Post newspaper wrote, per Express. "The city government there has set up a level one emergency response center. Onlookers are urged not to block access to emergency crews moving into the area."
The USGS said the quake was very shallow, at a depth of 6.2 miles (10 km), which would have amplified its effects.
People in Taiwan reported on Twitter feeling the earthquake, with many saying it felt strong.
USGS
Taiwan's Central Weather Bureau also measured a second quake of 4.3 magnitude centered in Tainan.
According to the USGS, a magnitude 6.4 earthquake can cause severe damage.
Earthquake we just had in Taiwan is no joke. Hope all are safe in Tainan: https://t.co/TFE89Udjpe pic.twitter.com/dez5XZNhL4
- Holly (@taispy) February 5, 2016
An #Earthquake at Tainan, #Taiwan ,3:57(UTC+8), some buildings are collapsing. pic.twitter.com/zCaovMFims
- sogetsu (@sogetsuchang) February 5, 2016
PHOTOS: Buildings collapsed after 6.4 magnitude #earthquake strikes #Tainan, #Taiwan pic.twitter.com/aaY9ivpdOk
- Perfect Foundation (@PerfectFdn) February 5, 2016
The quake initially cut power to 168,000 households in Tainan, many of whose residents lived through a massive 1999 tremor that killed about 2,400 people. Later, utility Taipower said power had been restored to all but about 900 households.
Taiwan lies in the seismically active "Pacific Ring of Fire". Television quoted Tainan residents as saying the quake felt worse than the 1999 tremor, centered in central Taiwan.
China's Taiwan Affairs Office, which in is charge of Beijing's relations with the self-ruled island, said China was willing to provide help if needed, Chinese state news agency Xinhua said. Beijing regards Taiwan as a wayward province.
REUTERS/Stringer
Firefighters hosed down part of the building to prevent a fire while others used ladders and a crane to enter upper floors. The building appeared to have collapsed onto the first story where a child's clothes fluttered on a laundry line.
REUTERS/Pichi Chuang
(Additional Reuters reporting by J.R. Wu, Faith Hung, Carol Lee, Eric Walsh, Eric Beech, Elizabeth Dilts and Ben Blanchard; Writing by Mark Bendeich; Editing by Tomasz Janowski, Robert Birsel)