As boaters hit the marinas and many others grilled feasts over the Fourth of July weekend, first responders were busy trying to keep roads and waters safe.

Austin police said 40 people were arrested during a “no-refusal” drunken driving initiative over the Fourth of July holiday weekend that began at 9 p.m. Friday and continued through 5 a.m. Sunday.

During a no-refusal period, officers can ask a judge to approve a search warrant to get a blood sample from those drivers who refuse to take a breath test for blood alcohol content.

Among those arrested were two people who faced charges of boating while intoxicated. One of them was a 55-year-old man who police said was operating a 23-foot Malibu ski boat at Lake Travis while under the influence of marijuana and alcohol, according to court records.

In a few cases, the outdoor activity on Central Texas rivers and lakes during the holiday weekend turned deadly.

An equipment malfunction on a boat Saturday may have resulted in the death of a 5-year-old girl on Lake Travis, a spokesman with the Texas Parks and Wildlife Department said.

Medics responded to a call around 3 p.m. at Lake Travis near Emerald Point Marina after Hailey Falk was struck by an unidentified object on the lake, officials said.

“The boat that she was in or with brought her to the marina, where she was met by first responders and STAR Flight,” said Rick Rutledge, a captain with Austin-Travis County Emergency Medical Services.

Medics began treating the girl at the marina before STAR Flight flew her to Dell Children’s Medical Center, where she was pronounced dead, officials said.

A preliminary autopsy report ruled Falk’s death as accidental, according to the Travis County medical examiner’s office.

The Texas Parks and Wildlife Department was investigating Falk’s death and did not release any other details Monday afternoon.

Meanwhile, authorities have not identified the bodies of two men who were recovered over the weekend from waters in eastern Travis County.

One of them, a man in his 20s, was found by a couple of kayakers in the Colorado River near 1901 Citation Drive in Garfield on Saturday. More than 20 hours before, divers had been looking for him after a woman called 911 saying she saw a man go into the water near Little Webberville Park in Webberville, according to the Travis County sheriff’s office.

On Monday, officials were still investigating the incident, and a medical examiner was still trying to determine the cause of death.

Late on Sunday, Austin police were looking into the death of a 40-year-old man who was found in the water at McKinney Falls State Park in Southeast Austin. The body was found floating in the water, but witnesses could not say when the man entered the water, officials said.

Total DWI arrests – 40

Total BWI arrests – 2

Number of breath samples – 17

Number of blood draws – 23

Number of search warrant blood draws – 18

Number of consent blood draws – 5