Lisa: In tonight's other news, parts of northern California are bracing for more rain as residents try to escape rising flood waters.

A combination of heavy rains and so-called king tides have led to dangerous driving conditions this weekend.

Several drivers had to be rescued from their cars in Marin county, just north of San Francisco.

King tides happen when the sun, moon, and Earth align in a way that brings tide levels to their highest.

More rain is expected across northern California through Monday, which the national weather service says could lead to flash flooding.

Overseas now, hundreds gathered to attend a church service and memorial for those killed in a new year's day fire in Switzerland.

People packed a local church and formed a procession to the makeshift shrine built for the victims.

At least 40 people were killed and more than 100 others injured when a fire erupted in a bar in the early hours of new year's day.

Swiss authorities announced this weekend they have opened a criminal investigation into the bar's managers after a preliminary investigation showed sparklers in champagne bottles likely caused the deadly blaze.

Moving to Nigeria where gunmen killed at least 30 people and abducted several others.

It happened overnight in a small village in the northern part of the country, near the area where 300 school children where kidnapped in November.

The gunmen stormed the village, opened fire on residents and razed the local market and houses.

Armed rogue gangs in Nigeria often target remote communities that don't have extensive security or government presence.

Still to come on pbs news weekend, a new approach to teaching medicine by teaching future doctors more about food.

And, how cutting edge ai is leading to insights about an ancient species, humpback whales.

>> This is pbs news weekend from the David M. Rubenstein studio at weta in Washington, home of the pbs news hour, weeknights on pbs.