2 dead as 6.4-magnitude earthquake leaves California town a 'total mess'

Two people are dead and a California town was left a "total mess" following a 6.4-magnitude earthquake that struck the coast, according to local officials.

There is no power or water in the city of Rio Dell after the earthquake caused a major water main break and shook homes off their foundations, a Humboldt County official said Tuesday morning.

The "notable" 6.4-magnitude earthquake struck the northern coast of California early Tuesday, the U.S. Geological Survey said.

Preliminary data placed the center of the quake along the Pacific Coast about 7.5 miles away from Ferndale, California, USGS said. The quake was recorded at about 2:34 a.m. local time.

Two people, a 72-year-old and an 83-year-old, were killed in Humboldt County as "a result of medical emergencies occurring during and/or just following the earthquake," officials said. Their preexisting medical conditions were exacerbated by the stress of the quake, officials said Wednesday.

At least 17 people were injured as a result of the earthquake, Humboldt County Sheriff William Honsal announced Wednesday afternoon.

California Gov. Gavin Newsom declared a state of emergency Tuesday evening in response to the quake.

"The emergency proclamation enables Humboldt County to access resources under the California Disaster Assistance Act, directs Caltrans to formally request immediate assistance through the Federal Highway Administration's Emergency Relief Program and supports impacted residents by easing access to unemployment benefits and waiving fees to replace records such as marriage and birth certificates, among other provisions," he said in a statement.

Multiple people were rescued Tuesday morning after they were trapped in a building that collapsed, Samantha Kargas, public information officer for the Humboldt County Sheriff's Office, told ABC News.

About 29,000 customers in Humboldt County were still without power Tuesday night, according to tracking website PowerOutage.us.

"Power is out across the county," officials said on Twitter, adding in all-caps: "Do not call 911 unless you are experiencing an immediate emergency."

The sheriff's office also said there was "widespread" damage to roads and homes throughout Humboldt County, including the Fernbridge in Ferndale. There were at least two injuries in the county, both from falls, a spokesperson for the sheriff's office said.

A home caught on fire when a water heater severed a gas line, Humboldt County officials said.

Approximately 15 homes have been red-tagged, meaning they suffered damage and have been deemed unsafe to go inside, while 18 homes have been yellow-tagged and have suffered moderate damage, according to county officials.

State Route 211 was closed at Fernbridge after the roadways and a bridge suffered possible seismic damage, according to the California Department of Transportation.

Significant damage was also recorded in Fortuna, where stores were seen with broken windows due to the tremors.

The quake was large enough to trigger a "ShakeAlert" that was sent to cellphones by FEMA's Wireless Emergency Alert System, officials said.

"We hope everyone is safe and if you felt shaking or got an alert you took a protective action like Drop, Cover, and Hold On," USGS said.

A tsunami wasn't expected, according to the U.S. National Tsunami Warning Center, which reported the quake at a preliminary magnitude of 6.1.

ABC News' Izzy Alvarez, Teddy Grant, Keith Harden, Liz Kreutz, Bonnie McLean, Lissette Rodriguez and Jennifer Watts contributed to this report.