Turns out that some people were harder to reach. Of the 13,239 landline phone numbers in the city's emergency alert system, only 7,828 people got a call about the alert on Nov. 10, according to the police department's analysis.
Police Cmdr. Dave Bertini explained why: Some lines were busy; some people hung up; some phone numbers no longer worked; and a proportion of calls stalled because of an overloaded network.
"We have changed the system settings as a result of Sunday," Cmdr. Bertini said. When Menlo Park first implemented the Blackboard Connect alert system about seven years ago, the system was programmed to make only one attempt at calling each number in its database. "We've now changed the settings to do three tries, with five minutes in between."
That's why some residents reported missing the first alert, but getting a call on Monday, he said. Still, although the second round reached 10,241 people, that leaves nearly 3,000 that didn't get a call.
The fire was "a watershed for people to sign up for alternate ways of getting notified," Cmdr. Bertini said. "We're really urging people to register."
But few people have signed up using their mobile and online contact information. Cmdr. Bertini said that only 2,174 email addresses and 604 cellphone numbers were registered via Blackboard Connect.
Of those, 732 emails bounced and 12 cellphone numbers didn't work during the recent alert, he said, so once someone has registered, it's critical that they keep the information updated.
Cmdr. Bertini said that during a mass emergency, such as an earthquake, the phone system is likely to go down.
"So if we try to put out 13,000 phone calls, there's a good chance none will make it out. But we learned some lessons from (the Boston Marathon bombing) — cellphone networks do get overloaded, but text messages squeeze through. If we put out a text, you'll get the emergency notification."
In addition, police posted the advisories about the fire on Facebook and Twitter. Particularly with more and more people eschewing a landline altogether, social media is playing a larger role in getting the word out during emergencies, according to the police.
Cmdr. Bertini noted that the notifications would have been handled differently had the "shelter in place" alert been an order instead of being optional.
Had it been mandatory, he said, the alerts would have stated that and officers would also have patrolled the streets announcing the "shelter in place" order via their PA systems.
People have said they're worried about getting inundated with messages from the city, and some have also raised privacy concerns. Blackboard Connect's database of listed and unlisted phone numbers, according to the police department, is used only for emergency alerts. NIXLE covers alerts as well as lower-level notices such as traffic advisories.
As for privacy, the city said the registered personal information is not shared with outside parties and will be used only for the purpose of notifications.
How to sign up
There are multiple options for emergency alert notification:
• Go to tinyurl.com/m32e2oy to sign up for the city's Blackboard Connect alerts.
• Register with NIXLE (local.nixle.com/register/)
• Go to menloparkpolice.org and fill out the alert registration form toward the bottom middle of the page.
• Contact Carolina Gaskin at the Menlo Park Police Department at 330-6327 or email@example.com with your name, street address, email address and phone number.
If you use a call-blocking service, add 650-330-6300 to the approved number list.