In the video below, you can see the moment that the bridge collapsed.
On Tuesday, another body was found in the Colorado River in neighboring Burnet County, sheriff's office Capt. Tom Dillard said.
More rain is forecast for Wednesday and Thursday and flood warnings remain in place for large parts of Texas.
The Llano River meets the Colorado River in Kingsland. Levels rose to just under 40 feet (12 meters) on Tuesday but fell as the morning progressed, settling at little more than 35 feet (11 meters), according to the National Weather Service.
Llano County emergency management coordinator Ron Anderson reported roughly 105 people being evacuated on Tuesday.
Texas Governor Greg Abbott ordered the State Operations Center to be ready to respond to severe weather and flooding on Tuesday morning. No one appeared to be on the bridge, and no injuries were immediately reported.
Houses near the Colorado were flooded, resident Terri Kleen said.
As the Llano River crested to its highest level since 1935, the FM 2900 bridge in Kingsland collapsed this morning around 9:15 a.m., according to KXAN.
Fire officials in Austin have temporarily banned all boating along the city's waterways as heavy rain and flooding create risky conditions. Three bodies have been recovered. Evacuations are underway in the cities of Kingsland and Marble Falls, both northwest of Austin.
Fast-moving water slammed against bridges, causing at least one to crumble under the flow. There, swollen river water rushed against the top of the 2900 bridge for hours, eventually causing it to collapse, video from CNN affiliate KEYE showed. "Seek higher ground!" the National Weather Service tweeted.
The river was expected to crest at near 41 feet (12.5 meters), which is 18 feet (5.5 meters) above major flood stage.
Water on the Llano is cresting at almost 40 feet (12 meters), just shy of the record of 41.5 feet.