Young adventurer Lisa Tam Chung, a South Grand Prairie High School graduate who was brain-dead and on a respirator after a boating accident near Cancun, died Tuesday in a north Texas hospital, an official with the Dallas medical examiner's office said.

Students at South Grand Prairie high are planning to have a candlelight memorial for Wednesday starting at 8:30 p.m. There may be another gathering on Friday night as well.

The ceremony will be near the flagpole on the school campus.

Chung and a group of teens were on a post-graduation senior trip last weekend when the catarmaran they were on partially sank near Cancun Mexico.

Chung was with a group of eight South Grand Prairie graduates when the boat foundered with about 120 aboard and partially sank, stern down, under clear skies about 1 p.m. local time. It was eventually towed ashore. The boat was on a snorkeling cruise with no destination, a representative of the company that arranged the trip said Monday.

John Cosme, 18, a member of the South Grand Prairie party, said he was on the upper deck of the two-level boat. Cosme said in a telephone interview from Mexico on Monday that crew members did not wait for passengers to get into life jackets before beginning to leave the vessel themselves.

Jay Wiggs said his son, Carson, 18, of Grand Prairie, told him that the crew left passengers -- perhaps 100 -- to fend for themselves.

"The crew basically said, 'Here's the life vest,' " Jay Wiggs said his son told him. "Next thing you know, the crew just took off."

Other South Grand Prairie graduates on the boat included Loren Dailey and Kyle Felts.

Cosme, Dailey and Wiggs returned home late Monday.

Cosme and Wiggs said that when the boat started taking on water, crew members threw snorkeling gear into the water and then left the boat, and several parents and students began handing out life jackets.

Cosme said that Dailey and Chung went into the water and were holding onto a rope tied between the foundering tourist boat and a rescue vessel. When the rope straightened and lifted the two girls halfway out of the water, they let go, Cosme said.

Another boat came over the top of the two girls, Cosme said, and he jumped in to help them. Cosme said he saw a man in blue trunks pull Dailey into a rescue boat, but he lost sight of Chung. He did not see her again until she was on shore and being attended by medical personnel.

Dailey suffered a bump to the head, Cosme said.

Dailey and Cosme later went to the hospital to check on their friend's condition and were told she was stable. They learned on Sunday, when Chung's mother and aunt arrived at the hospital, that the teen was brain dead, Cosme said.

Police say they are investigating whether the boat was overloaded, AP reported.

Ricardo Portugal Zubiata, a spokesman for the Red Cross in Cancun, said his agency treated people for injuries after they made land.

Workers treated five people for panic attacks, two who had fractured bones and Chung. Zubiata added that he wasn't aware of Chung's current condition.

Danh Thikim Chung, who was in Cancun, said her 18-year-old daughter was on summer break, and was going on a snorkeling trip on the boat named Sea Star, according to the Associated Press.

Wiggs said his son, Carson, thought the boat hit something. He said Carson told him, "It started taking on water and started sinking."

Late Monday, Carson Wiggs said, "It felt like we had run aground. The front of the boat was stuck but the back was moving."

Another parent, Ollie Dailey, said his daughter went into the sea with Chung after the vessel began taking on water.

"Our daughter called us and informed us that she had been involved in an accident... . It wasn't a school-sponsored trip," Dailey said. "We just know that they were involved in a boating accident."

Dailey said, "We're getting very limited information. There's a serious nature to the accident.

"They had life jackets on but they had to jump into the water," Dailey said. "They were trapped underwater. There's a student they're waiting to transport her back to the United States."

Dailey said a trust fund may be established for Chung. Her high school annual lists Chung as a three-time class favorite, a National Honor Society member and yearbook staffer.

She planned to enroll in Baylor University's honors program in the fall with a major in psychology and a minor in political science, according to her Facebook page.

Word of Chung's condition spread quickly.

"Honey bun i am praying for you," wrote classmate Marhiah Castorena on Chung's Facebook page. Other people also left messages on the page.

Dailey is listed as a 2008 cum laude South Grand Prairie graduate. Chung was also listed on the high school commencement announcement as a cum laude graduate.

Dailey said the group's trip was arranged through GradCity, headquartered in Peabody, Mass. The company's Web site advertises "... a graduation gift that you'll never forget."

GradCity has been in business since 1987 and books trips for about 50,000 annually, according to Jason Chute, operations director for the company.

Chute said the six-month-old, 75-foot boat had a capacity of 250 and was carrying about 120 when it went down.

The Sea Star is registered to a company named Aquatic Services of the Caribbean, Chute said. It carried a crew of five, plus a GradCity staff member. Chute countered the notion that the crew abandoned the passengers.

"The crew members who were reported leaving the boat went to get help," on shore, which was about 200 yards away, Chute said. "The response was very quick."

Pat Dailey has talked to her daughter several times since the accident.

"They told them to jump off the boat," she said. "She was one of the ones who was trapped.

"She said she felt like she had stopped breathing," Pat Dailey said. "She thought she had died. "She said the crew pretty much abandoned them. I can imagine the fear."

Dailey suffered a bump on the head, Cosme said. Pat Dailey said her daughter doesn't recall details of her rescue. "She just remembers that there was some guy in blue trunks," she said.