Crews resumed their search Monday for a 12-year-old Canadian girl who fell off a boat in San Diego's San Vicente Reservoir Saturday.
The first full-day search was halted at about 6:30 p.m. Sunday without lifeguards finding the girl and crews said it was tough to come back to the docks without answers.
"It's frustrating when you are in conditions that are a little bit hard to control than you are used to," San Diego Fire-Rescue (SDFD) Lt. Rich Stropky said.
The search, which SDFD officials were calling a recovery operation, resumed at 6 a.m. Monday, 36 hours after the girl fell off a ski boat. Four adults and two children were aboard the boat, San Diego police said.
Lt. Stropky said search crews deployed sonar devices, remote-operated vehicles and additional divers Monday.
The girl was visiting from Canada with several family members, SDPD Sgt. Bryan Brecht said. The couple operating the boat were locals.
The girl, who was wearing a life vest, was sitting near the bow of the boat when she fell, Stropky said. As the boat was slowing down, the bow was bouncing and the girl fell off the front, police said.
The family was tubing so the boat was towing a float, according to police.
The child's life preserver was later found and is now part of the investigation, Stropky said.
The reservoir water is clearer than some of the other reservoirs in the area and that is helpful in the search.
"Unlike the ocean, the water is not moving unless they open the dam then we are good, because what is in place on the bottom will likely stay there," Stropky said. "Now we just need to locate that area."
The reservoir is also deep. Past 120 feet, the water becomes murky and there are 15-foot trees and rocks that made it a real challenge, he said.
In addition to divers, crews used am Automated Underwater Vehicle equipped with SONAR and a camera.
"The AUV can cover this entire lake. It can be programmed to do that, it's just processing the data that is the most time-consuming part of that," Stropky said.
On Sunday, crews were able to zone in on an area where they believe the girl fell over. Shortly after the girl fell in, several adults jumped to find her; one of the adults came back on to the boat to make the 911 call, Stropky said.
"That was great because it gave us a point to track where the carrier can actually triangulate where that call was made from," he said. "That's a good thing for us, we're getting all the information to one area, however, it was still very challenging because of the terrain and the depth and the visibility."
While the search operation was handled by SDFD, SDPD is handling the investigation into the accident.
The boat was towed out of the water Sunday as part of the investigation, though no foul play was suspected, police said.
"We're going to document it, draw diagrams and put our whole report together," Brecht said. "It's just like a vehicle accident. You want to see if there are any marks or trace evidence on the item."
Saturday, crews searched for two hours before suspending the search because the conditions became too dangerous for divers and rescuers to operate.
Divers went down about 120 feet, with a water temperature of 62 degrees and a visibility of 25 feet.
SDFD spokeswoman Monica Munoz said the recovery mission can be dangerous.
"There are actual trees that are at the bottom," she told NBC 7. "So that makes it a very treacherous condition to deal with." SDFD estimates the reservoir's depth to be about 130 feet.
The girl was on the boat with several other adults and the boat was not powered on when she fell. But it was moving with the wind and current, Stropky said.
SDFD lifeguards, San Diego City Public Utilities Department ranger divers and the Lakeside Fire Department helped with the search.
"While we wish that it wasn’t under this circumstance that we’re putting this family back together, this is the way we’re going to do it, and these gentlemen are very driven to make that happen," Munoz said.
The reservoir continues to be closed for recreation activities while the search is ongoing.
— Brie Stimson contributed to this story