PORTLAND, Ore. (KOIN) — The search for the driver believed to have slid off the I-205 bridge Sunday has been hampered by poor visibility, according to officials.

Deputies returned to the area where investigators said Antonio Amaro Lopez’s Subaru Tribeca would have landed. The Multnomah County Sheriff’s Office said the area is large; north of Government Island, west of I-205, near Tri-Club Island.

The family of Antonio Amaro Lopez said he was driving this car when they believe he slid over the railing of the I-205 bridge (Lopez)

Visibility was reported to be only about six inches. Additionally, a swift current and lots of tree debris in the water have made the search especially challenging, according to MCSO.

Deputies have been using a rescue boat equipped with SONAR to scan the bottom of the Columbia River.

“Generally speaking, when SONAR indicates an object that deputies believe may be a vehicle–not debris–deputies will take coordinates,” MCSO told KOIN 6 Tuesday. “The Dive Team is then notified, and will dive on the object, based on personnel availability and weather and river conditions, to determine if it is a vehicle.”

Meantime, the family of Lopez told KOIN 6 it is not like him to vanish unannounced.

Antonio Amaro Lopez (Courtesy of Abi Amaro)

“He he has a six year old granddaughter,” said Abi Amaro, Antonio’s daughter. “We just need everybody’s help, whatever insight they have can help us.”

A GoFundMe page has been setup to help Amaro’s family

Officials said the search must conclude at sunset due to dangerous conditions.

Anyone with information is asked to contact Portland Police Officer Garret Dow, Garrett.Dow@portlandoregon.gov or 503-823-5070.