The Philadelphia School District is moving to a lottery-based kindergarten registration system for Penn Alexander in West Philadelphia, one of the city's most sought-after neighborhood schools.

Officials made the decision Friday after 70 parents gathered - with tents, chairs, takeout food, an RV, and a man erecting a temporary structure complete with plywood floors and insulation - ready to camp out for four days before registration began on Tuesday morning.

"There are safety issues involved," said Karyn Lynch, the district's head of student services. "There was a great deal of concern. And the decision was made to create the greatest amount of equity."

That means that the person who's first in line has the same shot at getting a spot as someone who registers on April 1, the deadline. Families will be notified of the outcome by early May.

The move infuriated many, especially those near the front of the line, who felt the district unfairly changed the rules mid-stream and left them with few options for alternatives if their children do not get into Penn Alexander.

Some said they were considering a class action lawsuit.

Others refused to leave their spots on Locust Street, saying they would camp out until they were allowed to register as initially planned.

A district official said the parents were free to stay, but that staying would not help their chances in the lottery.

"I could understand if they said, 'Ok, in the future, we will have a lottery,'" said one grandfather who traveled two hours to help his daughter and son-in-law coordinate waiting in line. "But to do it in the middle of the process, when people have relied on this, that's just unjust. This is a terrible way to treat people."

Like many interviewed, the grandfather asked to remain anonymous because he feared retribution for his family from the district.

Opened in 2001, Penn Alexander is unique in a district where there are few strong neighborhood schools - it gets $1,300 extra per student from the University of Pennsylvania, which also provides instructional support. When demand for spots in the school became more acute, Penn paid to add a fourth kindergarten class in September.

Residents pay a premium - roughly $100,000 extra - to live in the Penn Alexander catchment, and demand for seats now outstrips supply. And Penn Alexander's pre-kindergarten registration wait has gotten longer in recent years; the wait used to only be a few hours.

Some, however, applauded the decision.

At mid-afternoon, Terrence McGuckin, who was holding the spot of his friend, a single mother who was scrambing to make child care arrangements and gather provisions, proclaimed the four-day wait "totally ridiculous. It's totally driven by panic."

The decision was made the day after a Penn Alexander parent raised the issue at a School Reform Commission meeting.

"The way that we do this shouldn't be through who can stand in line the longest," David Lapp, whose child will be in kindergarten in the fall, told the SRC. What about single parents, he said, or people with childcare issues?

Chris Hiester lives across the street from the school and has a child who will be a kindergartener in the fall, but had vowed not to camp out.

"Part of it is practical," Hiester said. "I have three kids, and it would be a huge effort to be able to pull off having one of us, my wife or myself, be over in that line for four straight days."

But equity was also a concern, he said.

"It's a public school, and if we're still going to have it be a neighborhood school, it should be a lottery," said Hiester. "I think everyone should have the same shot."

Even before the lottery was announced, people were unhappy with the situation.

"None of us likes this," said one parent, who declined to give her name. "None of us wants to be here."

Liza Law was at her desk at Penn's Wharton School, where she is IT director, on Friday morning when she heard rumors the line was forming.

She ran out the door, taking the rest of the day off. She had formulated an extensive plan, involving food and phones and tents and childcare handoffs. Trading places in line throughout the weekend would be her parents, who live nearby, her sister and brother-in-law, who live in New York, and her husband.

Law was number 62 in line, a spot she said might not guarantee her child a place. There were 72 kindergarten spaces this year, but children with special education plans and those in Head Start programs get first dibs on the spots.

When the possibility of a lottery was raised, Law wasn't sure. If she was nearer to the front of the line, she wouldn't like losing her guranteed spot, she said.

But without a guaranteed slot, the lottery seemed like a good idea. "You pay a premium to live in this neighborhood," Law said, "but not everyone can wait in line."

Lynch, the district student-services chief, said the Penn Alexander kindergarten lottery would become a pilot, and in the future, if other schools have situations where there are more students than seats, a lottery would be used there, too.

As is the case currently, siblings of current Penn Alexander students will not be given any special treatment, she said. That point also angered some parents with children already enrolled in the school.

Children who do not win a spot in the kindergarten lottery, will be offered seats in the kindergarten classes at schools geographically closest to Penn Alexander, such as Lea Elementary.