Angela Chao, the chief executive of a shipping company and part of a prominent family in American politics, was legally intoxicated when she drove into a pond in Texas and died last month, according to a police report released on Wednesday, which called the episode an “unfortunate accident.”

The report, released by the Blanco County Sheriff’s Office, describes a harrowing scene on the night of Feb. 10 as friends and deputies tried frantically to pull Ms. Chao from her Tesla, after she drove it into the pond at a family ranch in Johnson City, Texas.

Earlier that night, Ms. Chao, 50, had dinner with a group of friends at a guest lodge at the ranch, the report states. At about 11:30 p.m., the guests began to return to their bedrooms or to their homes. Ms. Chao then got into her Tesla and reversed into the pond, the report states.

A friend told investigators that Ms. Chao called her at 11:42 p.m. to tell her that her car was in the pond and that she couldn’t get out of it. The water was rising, and Ms. Chao said “she was going to die and said ‘I love you,’” before the Tesla went under the water, the report states. The conversation lasted about eight minutes.

The friend then got into a kayak and paddled toward the Tesla, as another friend got into the water, swam to the vehicle and climbed on top of it, trying to find Ms. Chao, the report states. A third friend contacted 911 at 11:55 p.m. and remained on the phone for 11 minutes, the report states.

When law enforcement officials and firefighters arrived, they entered the cold water and tried to enter the car, the report states. The driver’s door window was broken, and a deputy went underwater and began feeling around the car until he found Ms. Chao.