LONDON — British Defense Secretary Grant Shapps and other top officials were on board a Royal Navy nuclear submarine when the test-firing of a Trident II 5 nuclear missile failed last month.

The misfire saw the missile crash back into the sea close to the submarine HMS Vanguard which was undertaking demonstration and shakedown operations off the coast of Florida following a seven-year deep maintenance program.

Shapps confirmed the failure in a Feb. 21 statement to parliament after reports of the Jan. 30 incident appeared up in The Sun newspaper here.

It’s the second Trident test firing in a row that has gone wrong for the Royal Navy. The previous misfire took place in 2016 when a missile veered off course and was destroyed.

Shapps was accompanied onboard HMS Vanguard by Britain’s top sailor, Adm. Sir Ben Key, numerous media outlets have reported.

Defence Procurement Minister James Cartlidge, appearing before a parliamentary Defence Committee on a separate topic on Feb. 21, confirmed that he too had been onboard along with senior unnamed U.S. officials.

Cartlidge declined to comment on a question from a committee member suggesting the failure was unrelated related to the missile itself.

The Sun newspaper, which broke the story, reported that a Trident 2 was propelled into the air by compressed gas in its launch tube but that its first-stage boosters did not ignite.

“On this occasion, an anomaly did occur, but it was event specific and there are no implications for the reliability of the wider Trident missile systems and stockpiles,” Shapps told lawmakers. “Nor are there any implications for our ability to fire our nuclear weapons, should the circumstances arise in which we need to do so.”

He added that the government “has absolute confidence that the U.K.’s deterrent remains effective, dependable, and formidable.”

The two misfirings by the British are in contrast to the performance of the U.S. Navy which also operates the Trident D5.

The last test of an unarmed missile by the USN took place last September when the Ohio-class boat USS Louisiana fired the weapon off the coast of San Diego, California.

Like HMS Vanguard, USS Louisiana was undergoing a demonstration and shakedown operation at the time of the firing.

Despite the British misfiring Shapps said the submarine and crew were successfully certified and will rejoin the operational cycle as planned.

Vanguard is part of a four-strong fleet of nuclear missile-armed submarines operating with at least one submarine being at sea and operational at all times.

The aging submarine fleet is scheduled to be replaced starting early in the next decade by a fleet of four Dreadnought-class boats now under construction by BAE Systems at its Barrow-in-Furniss yard.

Andrew Chuter is the United Kingdom correspondent for Defense News.