HOLLYWOOD — The first one went at 7:40 on a Tuesday evening and came back at 1:15 in the morning. The second went at 4:05 on a Thursday afternoon and came back at 9:50 that night. Both times it was 99 degrees or hotter. Both times it was the same three blocks of Franklin Avenue and the same handful of side streets running north off it, and nothing else.

That specificity is why there is now a group text with 41 people in it.

“After the first one, everybody stood in the street and complained,” said Odell Marchetti, 63, who has managed a 24-unit building on the block for eleven years and started the thread the following morning. “After the second one, somebody said the word ‘again’ and we all realized we didn’t actually know how many times. So now we write it down. Time it goes, time it comes back, and whether the crew showed up.”

The utility’s account of the two events is the same account it gives for most of them: equipment on the local distribution network failed under load, crews were dispatched, service was restored. Both incidents were logged as unplanned outages affecting fewer than 400 customers. A spokesman said the July heat has driven demand to the top of the seasonal range and that failures in that range concentrate in the oldest sections of the network, where underground cable and pole-mounted transformers installed in the 1950s and 60s are carrying loads nobody designed them for.

He also said, when pressed, that the department does not consider two outages in nine days on the same circuit unusual during a heat event. Several residents found that sentence more alarming than reassuring.

The practical cost of six and then six more hours without power is not evenly shared, and the block has worked out precisely who carries it. Two households on the thread have someone on a home oxygen concentrator. One has a refrigerator full of insulin. A man in his eighties on Bronson has an elevator in his building, which is to say he does not have an elevator for the duration of an outage, which is to say he does not leave the fourth floor. The taqueria on the corner threw out $600 of product after the Thursday outage and has taken to icing down its walk-in as a precaution whenever the forecast reaches triple digits — a cost, its owner noted, that is not reimbursable and not insurable at a premium he can pay.

What the group text has produced, besides a record, is a small amount of coordination. Two people with window units and working power on the far side of Franklin have offered their living rooms. A nurse who lives mid-block has the oxygen households’ numbers. Mr. Marchetti has a list of which apartments have residents over 75 and has knocked on all of them twice.

None of this is a plan, he is careful to say. It is a phone tree, which is what a neighborhood assembles when it does not have a plan.

The council office for the district said it has asked the utility for the outage history on the affected circuits going back three years and for any scheduled upgrade work in the area. The utility said the request is being processed. Residents at a hastily arranged Tuesday meeting in the taqueria’s back room — 30-odd people, one extension cord, a fan — asked for something narrower and more concrete: a text message when a crew is dispatched, so that people on the fourth floor know whether to start down the stairs.

That request, the council staffer present acknowledged, has been made before, in other neighborhoods, and has not yet produced a text message.

The heat broke on Friday. The thread has been quiet since, apart from one message on Sunday evening from a resident who reported her lights had dimmed for about two seconds and asked whether anyone else had seen it. Nine people said they had. Four of them wrote down the time.